The evolution of Japanese destroyers after WWII

Article written by Jon Harris 
Additional information, photos and graphs by D-Mitch

JMSDF destroyers (DDG and DDH) in formation

Since the end of World War Two, Japan has commissioned as many different destroyer type designs as the United States and the former Soviet Union. This exceptional feat has gone little noticed. The Japanese Maritime Self Defense Force (JMSDF) has produced a steady stream of gradually improving designs, culminating in the powerful, well-balanced fleet of today. Their design bureau didn't produce radical forms such as the Russian KYNDA class cruisers, or Swedish VISBY class corvettes. Rather, this island nation developed a variety of platforms designed to defend the homeland and its vital oceanic trade. The application of existing weapons and sensors, primarily of US origin, provided for robust growth, and limited expenditures on research and development.

A massive fleet of Japanese destroyers in formation

As of 2016, the JMSDF operates a total of 50 destroyers including; four (4) helicopter destroyers of three different classes (IZUMO, HYUGA, SHIRANE), eight (8) anti-aircraft warfare (AAW) destroyers of three different classes (ATAGO, KONGOU, HATAKAZE), 18 destroyers of three different classes (AKIZUKI, TAKANAMI, MURASAME), 11 small destroyers similar in size to frigates of two different classes (ASAGIRI, HATSUYUKI), six (6) destroyer escorts of the ABUKUMA class (similar in size to light frigates and corvettes) and three (3) small SHIMAYUKI class (reconverted HATSUYUKI-class) destroyers that are used mainly for training purposes but they keep all their armament intact. But let's go back some decades ago...

Asekaze (Gleaves) class destroyer

Ariake (Fletcher) class destroyer

Asahi (Cannon) class destroyer escort

Until 1956, Japan was relying on US-built destroyer designs such as the two ships of ASAKAZE (Gleaves) class, the two ships of ARIAKE (Fletcher) class and the two ships of the ASAHI (Cannon) class. The 1953 JMSDF program produced the first post WWII destroyer/destroyer escort designs. The poetically monikered destroyer escort AKEBONO ("Dawn"), an obvious and appropriate reference, initiated the new era in Japanese naval affairs when she was commissioned in 1956. In terms of size, armament and purpose, the AKEBONOs followed the United States Navy's approach to destroyer escorts (DE). The only palpable differences are that her designers chose steam turbines, for a 50% increase power over US war built DEs, and the use of two shafts, where US practice rigidly adhered to one. This gave the AKEBONOs a more useful 28 knot top speed, and perhaps increased her comparative maneuverability and survivability. Notably, Japan will adhere to the DE design principle of austerity for the next 50 years, while the USN veered away from this approach by the end of the 1950s.

Akebono, Ikazuchi and Inazuma destroyer escorts

Near sisters to the AKEBONO, is the diesel-powered pair, Ikazuchi and Inazuma of the IKAZUCHI class destroyer escorts. The diesels change the dimensions a bit, reduce the speed to 25 knots, and allow a reduction in complement.

Harukaze class destroyer

Destroyers Harukaze and Yukikaze of the HARUKAZE class were also included in the 1953 program. These two were the first indigenous destroyers (DD). Conventional in design, with a topside layout closely following the then contemporary US FORREST SHERMAN class. Japanese designers also mimicked the FORREST SHERMAN's use of steel for the hull, and weight saving aluminum for the superstructure. A flush deck was employed for the first time on a Japanese destroyer. The armament was a throwback to the late war US pattern, with 5" 38 caliber dual-purpose guns, 40mm AA guns, hedgehogs, K guns, and depth charge racks. This set a decade long pattern of equipping JMSDF ships with technology that had a significant lag from US practice. The HARUKAZE's machinery generated 30,000 SHP, which was short of the 50,000 SHP generated by a similarly sized US GLEAVES class vessel, and limited the speed to 30 knots. Certainly this was adequate, but shy of the 35-knot then contemporary expectation for destroyer types.

Ayanami class destroyer

The AYANAMI class followed in the 1955, 7 and 8 programs. Having the same 1700 ton standard displacement as the HARUKAZEs, but quite different in arrangement and purpose. Rated as DDKs (anti-submarine destroyers), with a primary ASW role. Their general appearance more closely follows Japanese war built ships, with an AKITSUKI style tall, curvilinear bridge structure. The broken deck returns with a long graceful sweep down to the quarterdeck. Like the AKITSUKIs, the AYANAMIs feature a light caliber gun primarily oriented for AA work. In this case, three twin, half shielded 3" 50 caliber guns. Two trainable hedgehogs are mounted forward of the bridge, along with Y guns, depth charge racks, and 4 fixed tubes for AS torpedoes. There is also a quad mount for 21" anti surface torpedoes.

Murasame class destroyer

The seven AYANAMIs are joined by the three 1800-ton MURASAME class destroyers of 1956-7. Here the JMSDF reprise the HARUKAZE class gun arrangement, but use 5" 54 caliber guns in lieu of 5" 38 caliber, and substitute twin, shielded 3" 50 caliber guns for the 40 mm weapons. The 5" 54s are an interesting reuse of units dropped from American MIDWAY class aircraft carriers. This practice emphasizes the close cooperation between the two navies. The heavy AA battery of the MURASAME is augmented by a fixed hedgehog, 8 ASW torpedoes, a Y gun, and a depth charge rack. Like the HARUKAZE, the 2 sets of geared turbines generate 30,000 S.H.P., providing a limited, but adequate 30-knot speed. To this point, JMSDF designers are clearly holding the line on ship size, and eschewing great increases in horsepower that provide only a small increase in top speed. A doubling of horsepower would likely mean a 5-knot top speed increase, but 30 knots is fine for escort work. Indeed, current worldwide destroyer/frigate designs seem to have accepted this approximate speed as the most reasonable balance of cost and capability.

Akizuki class destroyer

An expanded version of the MURASAME is manifested in the 2350-ton AKIZUKI class of 1957. Designed as a pair of flotilla leaders, they have a slightly larger bridge structure, an extra hedgehog, a Mark 108 (Weapon Alpha) ASW rocket launcher (Akizuki) or one Bofors M/50 375mm multiple ASW rocket launcher (Teruzuki), a bank a quad 21" torpedoes (complete with reloads), and 50% increase in power and complement.

JDS Wakaba

Upon completion of the AKIZUKIs in 1960, the JMSDF had completed 17 destroyer type ships from the keel up in 7 years. This, along with the transfer of 24 destroyer/frigate types from the United States, and a raised war built vessel (Wakaba), gave the JMSDF 42 ocean going combatants. A tiny coastal fleet had been transformed into a large capable navy in a few short years, a phenomenal achievement.

Isuzu class destroyer

The early sixties saw the pace of construction relax a bit while all of these new vessels were being absorbed into the fleet. The 1959 and 1961 programs each fund a pair of IZUZU class DEs. This time the standard displacement increases almost 50% to 1490 tons, still putting them at about the size of the late war built US DEs of the RUDDEROW class. The lead ship commissions with a pair of shielded 3" 50s, a Mk.108 Weapon Alpha (it was changed with a 4-barreled 375mm Bofors ASW rocket launcher in the latter batch as the American ASW launcher did not satisfy the requirements), the first JMSDF appearance of the now ubiquitous triple ASW torpedo launchers, along with a depth charge thrower and rack. Later, Weapon Alpha of the earlier batch was also replaced by a Type 71, Japanese version of the M/50 Swedish 375mm quadruple ASW rocket launcher. Diesels power two shafts capable of propelling each of the four ships to 25 knots.

Amatsukaze class guided-missile destroyer

The 1960 program funds the first JMSDF ship to wield surface-to-air guided missiles. The AMATSUKAZE (DDG) is significantly larger than its forbearers at 3050 tons, and is fitted with a single arm Mk 13 Tartar launcher aft, space for an ASROC launcher between the funnels (it was installed later), ASW torpedoes, and a pair of twin superfiring shielded 3" 50s before the bridge. The bridge superstructure itself is an enclosed rectangular block similar to US warships of the period. An unusually tall pair of funnels enables stack gasses to clear the SPG-51 missile fire control radars. The quarterdeck is cleared for helicopter operations. Geared turbines can drive the vessel at top speed of 33 knots. The vessel was upgraded later by receiving SM-1 missiles, Mk-32 triple torpedo launchers and other electronic equipment. The technological lag of the earlier JMSDF era is now closing. The first Italian DDG, Impavido of the IMPAVIDO class, completed only 15 months earlier, the HMS Devonshire first of the COUNTY class destroyers only a year earlier than Impavido. Australia will not complete the HMAS Perth, lead ship of a modified version of the CHARLES F. ADAMS design of a  until several months after AMATSUKAZE commissions.

Yamagumo class destroyer escort

Minegumo class destroyer escort

Until the 1962 JMSDF program, the distinction between the design and function of the destroyer versus destroyer escort are clear cut. The destroyers are larger, heavily armed, and of a high speed which enables them to accompany fleet units. The destroyer escorts are relatively small utility vessels suitable for convoy and coastal work. With the YAMAGUMO class of 1962 we get a diesel-powered destroyer that blurs this distinction. This situation mimics what is occurring in other navies where the demand for sophisticated warships is tempered by the need to control costs. The 2050 ton, 27 knot anti submarine ships have two variants. Both carry a pair of twin 3" 50 caliber enclosed guns, a quad Bofors rocket launcher, and a pair of triple torpedo launchers. However, the YAMAGUMO's have an ASROC launcher (the first in the JMSDF) between a pair of funnels, while the single stacked MINEGUMOs carry a DASH (Drone Anti Submarine Helicopter) hanger and landing pad aft. It is interesting to note that the Japanese had much greater success with the DASH system than did the Americans. Ultimately, nine YAMAGUMO/MINEGUMO units were completed in a somewhat protracted program between 1966-78. Finally, about a decade later after their commission, in all MINEGUMOs the facility of DASH was removed in and the ASROC launcher was fitted.

Takatsuki class destroyer (initial configuration)

Takatsuki class destroyer after their modernization

The powerful TAKATSUKI class of 1963 puts an emphatic end to the JMSDF technological lag. The new Japanese destroyers are equipped and armed in the same manner as the contemporaneous American KNOX class. The major difference is that the Japanese manage an extra Mk 42 5" gun, a Bofors rocket launcher, and about 5 knots of additional speed on the same size hull as the American vessels. American ships of the period were generally criticized as being oversized and under armed. Certainly, the KNOX class was designed for long-term operations beyond that of the JMSDF, and this may have required more internal volume. Nevertheless, the TAKATSUKI's meet the weapon requirements that the Americans were looking for, but unable to procure, in the mid 1960s. They have a fore and aft 5" gun, ASROC, DASH, torpedoes, along with a 30 knot sustained speed. In the late ‘80s, two ships of the class, Takatsuki and Kikuzuki, were upgraded with Sea Sparrow SAM launchers, Harpoon missile launchers and even a Phalanx CIWS system (Kikuzuki only). The TAKATSUKI's introduce the sharply raked stem and macks (combined mast and Stack) to the JMSDF warship profile. This, along with the US weapons fit, make them seem to appear as American naval vessels to the casual observer.

Chikugo class destroyer

Returning to destroyer escorts, the 1967 program introduces the CHIKUGO class. Again, holding the line on displacement and dimensions to US World War II practice, the JMSDF manage to mount an ASROC launcher (the first Japanese destroyer escort class to carry the system), along with the more predictable gunhoused twin 3" 50 caliber, a twin 40mm, a pair of 324mm torpedo tubes, and a depth charge rack on this relatively small platform. Their designers apparently accept that the perfect escort is not obtainable at a cost that allows a sufficient number of hulls in the water. Working within these limitations, they still were able to produce a ship with an ASW battery of American GEARING FRAM I destroyer. Eleven units were commissioned between 1970-77. Technically outside of the destroyer/destroyer escort category are the minelayer Sooya (1971), minesweeper tender Hayase (1972), and training ships Azuma (1969) and Katori (1969). All of which are armed in the manner of destroyer escorts, complete with ASW systems. Their potential dual roles provide the JMSDF with simple force multipliers in the event of a conflict.

Haruna class helicopter carrying destroyer

Haruna class helicopter carrying destroyer

 With the commissioning of the Haruna in 1973 the JMSDF moves away from the US paradigm and takes a cue from the Italians. The 5000-ton Italian missile cruiser/helicopter carrier ANDREA DORIA class appeared in 1964. Authorized in 1967, the 4700-ton HARUNA class helicopter carrying destroyers (DDH) drop area air defense in favor of a heavy ASW battery. They carry three large HSS-2B Sea King helicopters, an ASROC launcher, the usual pair of triple 324mm torpedo tubes, along with 2 superfiring 5"54 caliber guns. Having a destroyer sized ship deploy multiple helicopters seems to make tactical sense, as a single ship can keep a bird in the air continuously. Other navies used this concept more ambitiously on much larger platforms, combining area air defense (MOSKVA class, VITTORIO VENETO class) and even strike aircraft (INVINCIBLE), making for more of a capital ship. The United States planned, but did not complete, a modified SPRUANCE capable of carrying four helicopters.

Shirane class helicopter carrying destroyer with the old Mk25 SAM launcher

Shirane class helicopter carrying destroyer after their modernization

Following the completion of the Haruna's sister Hiei in 1974, an enlarged pair is ordered in 1975-76, the SHIRANE class destroyers. Shirane and Kurama are 20' longer and have a modified silhouette with a second mack, one of which supports an OPS-12 3D radar. They also ship an octuple Mark 25 Sea Sparrow SAM launcher, the first and only appearance of this particular weapon in a JMSDF vessel. Were these surplus US units, supplied in the same fashion as the old MIDWAY 5”54s to the MURASAMEs in the 1950s? In any case, the under-powered missiles fired by the Mk 25s were soon supplanted by Mk 29 launchers that became a “standard” for the JMSDF ships till the introduction into service of the first destroyers with vertical launching systems.Of the two ships, only Kurama is active today and she is about to be replaced by Kaga, the second Izumo-class helicopter carrier.

Tachikaze class guided missile destroyer

Eleven years after the completion of the AMATSUKAZE, Japan's second DDG, Tachikaze, lead ship of the TACHIKAZE class enter the fleet. This extreme lag demonstrates a low priority or perceived importance in the role of fleet air defense. Fore and aft 5" guns, ASROC, a pair of triple torpedo tubes, complement a single arm Tarter D launcher that fires RIM 60A Standard missiles. Though the layout is different, the armament and size of these ships is nearly identical to the CHARLES F. ADAMS class, which were highly regarded in U.S. service. Sisters Asakase and Sawakaze follow in 1979 and 1983. In 1998, Tachikaze was converted to a flagship of the Fleet Escort Force thus the aft 5-inch gun was replaced with a fleet command area.

Hatsuyuki class destroyer

The year 1977 brings the authorization of the HATSUYUKI class of destroyer. This signals the beginning of series production of destroyers for the JMSDF. Previous classes with the exception of the CHICUGO class of destroyer escorts, have generally come in small batches, with orders sometimes coming years apart. For the next ten years, two and three units will be laid down every year, except 1985, when only one will commence with the changeover in class design. The HATSUYUKI manifests a number of different approaches for the JMSDF, such as, gas turbines being employed for the first time outside of a fast attack craft. The Italians are called on again for an armament change, and they provide the OTO Melera compact 76mm gun that is mounted forward. SSMs and CIWS appear for the first time in a JMSDF destroyer, with quad Harpoon launchers flanking the funnel and a pair of Phalanx Mk 15s atop the bridge superstructure. The 2950 ton, 426' ships are as elaborately equipped as the German BREMEN class of frigates, which are of nearly identical size and period. A complete chaff, ESM, and ECM fit protect against a range of threats. There is a full hangar and Beartrap equipped landing pad (a first for a Japanese general purpose destroyer) for a Sea King or Seahawk helicopter. ASROC and 324mm torpedoes can be used in conjunction with the bow mounted or towed sonar. A Mk 29 Sea Sparrow launcher is placed between the landing pad and the stepped down quarterdeck; the first destroyer class in the JMSDF equipped with the Sea Sparrow launcher.Of the twelve ships of the class, only two are part of the Fleet while 3-4 ships serve as training vessels.

Ishikari class destroyer escort

Yubari class destroyer escort

Also in the 1977 program is the destroyer escort Ishikari, sole ship of the ISHIKARI class. This time, the 1290-ton displacement and 278' length are actually less than a World War II vessel! How Japanese designers resist the temptation to enlarge and complicate is worth pondering in light of a continuing trend in ever larger and more expensive warships elsewhere. The OTO Melera 76mm gun supersedes the US Mk 33 3" 50 caliber gun that had been in use for about 25 years. The stern mounted Harpoon SSM launchers signal a more general purpose approach in utility. She was the first JMSDF destroyer escort with a gas turbine engine and surface-to-surface missiles. However, a quad Bofors launcher and pair of 324mm torpedo tubes maintain an ASW capability. Slightly enlarged nears sisters Yubari and Yebetsu of the YUBARI class follow in 1983-84.

Hatakaze class guided missile destroyer followed by an Asagiri class destroyer

The next pair of DDGs, Hatakaze and Shimakaze of the HATAKAZE class, rework the TACHIKAZE design. Gas turbines replace steam turbines, leading to a single, large squat funnel midships and ending the era of the MACK. The Mk 13 Standard launcher is moved to just aft the bow bulwarks, followed by a platformed 5" 54 , and then the ASROC launcher. Quad Harpoons flank the funnel, and a pair of Mk 15 Phalanx guns are abreast of a squat mainmast that supports the Japanese designed OPS-11C air search radar. Another 5" 54 is aft just before the helicopter landing pad. This 5" guns are curious for two reasons. First, a helicopter hanger in place of the aft mount would seem to be more useful. Secondly, the use of the old Mk 42 mount long after it was no longer being installed on new construction U.S. warships.

Hatakaze class destroyer moored next to two Asagiri class destroyers

Asagiri class destroyer

The JDS Asagiri is authorized in 1983, and becomes that lone destroyer alluded to earlier that was laid down in 1985. She is an enlarged and improved HATSUYUKI class destroyer, differentiated by twin funnels and a mainmast. Presumably, the earlier class proved to be cramped, as there is no fundamental change in the outfitting the ASAGIRI class, despite displacing 500 additional tons. Eight units are in commission by 1991.

Abukuma class destroyer escort

With the destroyer escorts of the ABUKUMA class, an effort to pack the general utility of the YUBARI, with the ASW punch of the CHIKUGO results in a ship that finally cracks the 2000-ton mark, barely, at 2050 tons. Unlike, the spare ISHIKARI and the two YUBARIs, they carry an air search radar, OPS-14C, and space for an SQR-19 towed array. The horsepower generated by the CODOG machinery is kicked up a bit for a slightly higher speed of 27 knots. A 76mm OTO Melera gun mount is forward, ASROC between the stacks, followed by torpedo tubes, Harpoon and 20mm Phalanx CIWS. Six ships were completed during 1989-93. These were the last Japanese destroyer escorts till today and the only active ones.

Kongou class AEGIS guided missile destroyer

A RIM-161 Standard Missile 3
launched from JDS Kongō

After years of regarding air defense as secondary to ASW, the JMSDF take a tremendous leap forward with the KONGOU class of 1987. Kongou's 1993 commissioning is almost a decade ahead of comparable European designs, the Spanish ALVARO DE BAZAN and the Dutch DE ZEVEN PROVINCIEN classes. In this application of advanced air defense technology (Aegis fire control system and long range SM-2 SAM), the JMSDF no longer lags behind other sophisticated naval powers. Although differing slightly in detail and fit, they could easily be taken for an American ARLEIGH BURKE class destroyer. The ships of the class are much larger than traditional destroyers and at 9,500 tons full load displacement come close to cruisers in size. They also give Japan a giant leap in capability with the eventual fit of the Standard SM-3 anti-ballistic missile, enabling defense of mainland Japan itself. The destroyers of the new class are the first Japanese destroyers that have stealth characteristics and the first ones equipped with the OTO Melara 127 mm (5 in)/54 caliber gun and vertical launching system capable to launch RUM-139 anti-submarine rockets and of course SM-2/SM-3 surface-to-air missiles as it was already mentioned,

Almost all (8 out of 9) units of the Murasame class of destroyers!

Still, the JMSDF does not abandon series production of general purpose destroyers. The destroyers of MURASAME class of 1991 is 1000 tons heavier than an ASAGIRI class destroyers. The new design drops the mainmast and has less cluttered lines, in an attempt to reduce the radar cross section. Sea Sparrow/Evolved Sea Sparrow missiles and ASROC are deployed via Mk 48 and Mk 41vertical launchers respectively, while the CIWS mounts are positioned fore and aft, improving their field of fire over the amidships position. Measures are taken that manage to reduce the complement by 25% over the ASAGIRIs. Nine units were completed between 1996 and 2002.

Takanami class destroyer

The MURASAME's are followed by the TAKANAMI class of 1998. With the same hull and general layout of their predecessors, modifications to the TAKANAMI include substituting an OTO Breda 5" 54 for the 3" gun, and moving all of the missiles to the Mk 41 position just forward the bridge. In an apparent attempt at keeping the position dryer, it is raised off of the main deck. The QQR-2 towed sonar array supersedes the QQR-1, which has been employed since the HATSUYUKI hit the water. Both KONGOU and TAKANAMI use the Italian 5" mount, ending nearly 50 years of JMSDF employment of exclusively American 5" guns.

Four classes: Atago class, Hatakaze class, Kongou class and Takanami class

Atago class AEGIS guided-missile destroyer

Improving on the KONGOU, the ATAGO class of 2000 follows the lead of the U.S. ARLEIGH BURKE Flight IIA by adding a helicopter hanger, and employing the longer range, license built, American 5" 62 caliber gun in place of the 54 caliber mount. A taller bridge enables greater command capability, while the mast and stack design offer improved stealth characteristics. Their full load displacement exceeds the 10,000 tons (!), the first time for a JMSDF surface combat vessel. Finally, Japanese Type 90 SSMs supplant the Harpoon missiles. These are 21st century warships of the first rank.

Akizuki class ATECS destroyer

The lead ship off the Akizuki class destroyers

The AKIZUKI class of 2010 follows the TAKANAMI’s as improved general purpose fleet destroyers, but make a great leap in computing power, employing the Japanese developed ATECS battle management system (in similar principles to the American AEGIS system), enabling these four ships to act as escorts for the KONGOUs. Structurally, there are improved stealth features as well as fixed arrays on the outside corners of the fore and aft superstructures.

The three classes of "AEGIS" destroyers of the Japan Maritime Self-Defense Force

Hyūga's torpedo tubes. Photo: Phantom

16-cell VLS of Hyūga. Photo: Phantom

About three years earlier of the Akizuki's commission, the JSDF commissioned the third class of helicopter destroyers (DDH), the HYUGA class, the largest ships built for the Japanese navy since the WWII. The two ships of the class replaced the Harunas helicopter destroyers. Even the two vessels are called helicopter destroyers, their specifications (197m length, about 20,000t displacement) and characteristics (huge flight deck, enclosed hangar and two aircraft elevators) are comparable to light aircraft carriers. This is of course a clever way to comply with Japanese constitutional limitations. The ships can accommodate up to 24 medium-sized (SH-60) helicopters or a smaller number of larger helicopters, even though the official complement is reported as three SH-60 and one EH-101 or CH-53 helicopters. For their defense they are equipped with two Phalanx CIWS and a plethora of heavy machine guns but also with two 8-cell Mk41 VLS modules capable to launch 12 RUM-139 VL ASROC and 16 ESSM SAM (or a different configuration). Not only that, but they carry two triple 324 mm torpedo launchers! Thus the designation name of helicopter destroyer perhaps is somehow accurate even though they do not carry SSM. Notice also that the two vessels are equiped with the ATECS, the Japanese AEGIS. Details of the class you can enjoy here.

Hyūga class helicopter destroyers/light aircraft carriers

Izumo carrier next to a Kongo
class destroyer

The huge hangar of Izumo

Six years later, Japan commissions her largest vessel, the DDH-183 Izumo, a helicopter carrier of 248 meters length and of more than 27,000tons displacement. The new IZUMOS DDH is similar in characteristics (bridge, mast, electronics, elevators etc.) but is much larger than Hyūgas about 50 meters! Till today is the biggest warship in Japan's fleet since World War II with a second vessel to be in service around 2017 that will replace the last of the Shiranes, Kurama. The new "destroyer" is equipped with four CIWS (Phalanx and SeaRAM) but not with torpedo launchers or any kind of SAM. She has been described by the Chinese, as an “aircraft-carrier in disguise” as it carries up to 28 aircrafts (depending on the size of the aircraft). Officially her initial aircraft complement consists of only 7 ASW helicopters and two SAR helicopters. The ships has neither a ski-jump nor a catapult for launching fixed-wing aircraft thus she is only limited to those capable of STOVL (short take-off, vertical landing) operations such as the F-35B or V/STOL capabilities such as the V-22 Osprey. Up till now, the Japanese Ministry of Defense has not mentioned the possibility of introducing fixed-wing aircraft but perhaps in the future Japan will consider the transformation of the Izumos into actual conventional aircraft carriers.

Izumo, lead ship of the new DDH class of Japan

Recently, in July 2017, the first Asahi class destroyer, the latest surface combatant designed for the Japan Maritime Self Defense Force, started sea trials. The class consists of two vessels; the first ship entered service in March 2018 and the second will join the Navy in March of the next year. The class is an evolution of the Akizuki class which was mentioned in previous paragraphs. Asahi is the world's first warship to be fitted with an operational GaN-AESA (gallium nitride - active electronically scanned array) Multifunction Radar. Asahi's radar is based on the FCS-3A AESA radar system but uses GaN technology for improved performances. (source)

The lead ship of Asahi class destroyers during its sea trials in July 2017.
Photo via @tamotaro

The following image illustrates all post-WWII Japanese classes of destroyers (DD), guided missile destroyers (DDG), helicopter destroyers (DDH), helicopter destroyers/light aircraft carriers (DDH/CVL) and destroyer escorts (DE) in their final configuration. All the destroyer classes are depicted chronologically by date of commissioning.

The Japan Maritime Self Defense Force destroyers after WWII. For high resolution image click here.

The two following tables summarize all the classes of the Japanese destroyers after WWII. In each class, all the vessels in the class are reported, the period of service (year of commissioning of the lead ship in the class and year of decommissioning of the last ship in the class) as well as the displacement in order to highlight the evolution in the size through the decades.

Japanese destroyer escorts classes (DE). High resolution image here.

Japanese destroyer classes (DD, DDK, DDH, DDG). High resolution image here.