The are
helicopter
A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...
destroyer
In naval terminology, a destroyer is a fast, maneuverable, long-endurance warship intended to escort
larger vessels in a fleet, convoy, or carrier battle group and defend them against a wide range of general threats. They were conceived i ...
s in service with the
Japan Maritime Self-Defense Force
The , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy ( ...
(JMSDF). The official classification of these ships is DDH (
helicopter-carrying destroyer), which is accepted by the
United States Naval Institute
The United States Naval Institute (USNI) is a private non-profit military association that offers independent, nonpartisan forums for debate of national security issues. In addition to publishing magazines and books, the Naval Institute holds s ...
; in contrast, ''
Jane's Fighting Ships
''Janes Fighting Ships'' is an annual reference book of each country's warship, navy and coast guard, along with their weapons and aircraft. Included are ship names, construction data, size, speed, range, complement, engineering, armament, a ...
'' describes this official classification, but the classification is simply "
helicopter carrier".
The
ship
A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...
s of this class are currently the largest surface combatants of the JMSDF, taking over the mantle previously held by the s. The lead ship was officially unveiled at
Yokohama
is the List of cities in Japan, second-largest city in Japan by population as well as by area, and the country's most populous Municipalities of Japan, municipality. It is the capital and most populous city in Kanagawa Prefecture, with a popu ...
on 6 August 2013.
Both ships of the class are planned to operate
STOVL
A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically if it does not have a heavy payload) and land vertically (i.e. with no runway). The ...
Lockheed Martin F-35B Lightning II aircraft after modifications. The modifications have been controversial as some claim these ships seemingly violate Japan's post-World War II pacifist
constitution
A constitution is the aggregate of fundamental principles or established precedents that constitute the legal basis of a polity, organization or other type of entity, and commonly determines how that entity is to be governed.
When these pri ...
, which restricts the country from possessing highly offensive weapons, such as "attack aircraft carriers". However, according to the Japanese government’s definition, "attack aircraft carriers" refer specifically to carriers designed solely for nuclear bombers to conduct nuclear strikes. Aircraft carriers equipped with conventional fighter jets or attack aircraft—whether they are small light carriers or large nuclear-powered carriers—are not considered illegal. Thus, Japanese and US officials have stated the vessels are not in violation, describing the vessels as defensive.
Development
The Japanese
Ministry of Defense (MOD) first announced plans for the class on 23 November 2009. This ship's primary mission is
anti-submarine warfare
Anti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations ar ...
(ASW) but peacekeeping and disaster relief operations are also being considered.

The ship carries up to 28 aircraft.
However, only 7 ASW helicopters and 2
search and rescue
Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger. The general field of search and rescue includes many specialty sub-fields, typically determined by the type of terrain the search ...
(SAR) helicopters are planned for the initial aircraft complement. For other operations, 400 troops and 50 3.5 ton trucks (or equivalent equipment) can also be carried. The flight deck has 5 helicopter landing spots that allow simultaneous landings or take-offs. The ship is equipped with 2
Phalanx CIWS
The Phalanx CIWS () is an automated gun-based close-in weapon system to defend military watercraft automatically against incoming threats such as aircraft, missiles, and small boats. It was designed and manufactured by the General Dynamics Co ...
and 2
SeaRAM for its defense. The destroyers of this class were initially intended to replace the two ships of the , which were originally scheduled to begin decommissioning in FY2014.
In 2010, Forecast International reported that some design features were intended to support fixed wing aircraft such as the
Bell Boeing V-22 Osprey and
Lockheed Martin F-35 Lightning II
The Lockheed Martin F-35 Lightning II is an American family of single-seat, single-engine, supersonic Stealth aircraft, stealth strike fighters. A multirole combat aircraft designed for both Air superiority fighter, air superiority and att ...
, although neither the MOD nor the JMSDF have mentioned the possibility of introducing
carrier-based fixed-wing aircraft.
The ship has neither a
"ski-jump" nor a
catapult
A catapult is a ballistics, ballistic device used to launch a projectile at a great distance without the aid of gunpowder or other propellants – particularly various types of ancient and medieval siege engines. A catapult uses the sudden rel ...
, typical features for launching fixed-wing aircraft.
The construction of the first ship of the class began in 2011 at an
IHI Marine United shipyard in Yokohama,
with funding totalling 113.9 billion yen ($1.5 billion) being set aside in the fiscal 2010 budget for this purpose.
Ships in the class
In September 2011, ''
The Asahi Shimbun
is a Japanese daily newspaper founded in 1879. It is one of the oldest newspapers in Japan and Asia, and is considered a newspaper of record for Japan.
The ''Asahi Shimbun'' is one of the five largest newspapers in Japan along with the ''Yom ...
'' reported that the Ministry of Defense was to proceed with a budget request calling for funds for the construction of the planned second unit in the class. The request was approved and the construction contract was awarded to
IHI Corporation
, formerly known as is a Japanese engineering corporation headquartered in Tokyo, Japan that produces and offers ships, space launch vehicles, aircraft engines, marine diesel engines, gas turbines, gas engines, railway systems, turbocharge ...
in October 2012. This will come under the Defense Ministry's Mid-Term Defense Program FY2011-2015. The first ship in the class, ''Izumo'' was launched on 6 August 2013. The ship was commissioned on 25 March 2015.
''Izumo'' was named after (present-day
Shimane Prefecture
is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Shimane Prefecture is the List of Japanese prefectures by population, second-least populous prefecture of Japan at 665,205 (February 1, 2021) and has a ge ...
), and ''Kaga'' after (present-day
Ishikawa Prefecture
is a Prefectures of Japan, prefecture of Japan located in the Chūbu region of Honshu island. Ishikawa Prefecture has a population of 1,096,721 (1 January 2025) and has a geographic area of 4,186 Square kilometre, km2 (1,616 sq mi). Ishikawa Pr ...
).
Modifications to accommodate STOVL operations

On 6 August 2013, was unveiled in
Yokohama
is the List of cities in Japan, second-largest city in Japan by population as well as by area, and the country's most populous Municipalities of Japan, municipality. It is the capital and most populous city in Kanagawa Prefecture, with a popu ...
, south of
Tokyo
Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...
, Japan. Japanese officials claimed it would be used in national defense, specifically citing anti-submarine warfare and border-area surveillance missions. Additionally, it is asserted to bolster Japan's ability to transport personnel and supplies in response to large-scale disasters. This unveiling occurred at a time of heightened tensions over the
Senkaku Islands
The Senkaku Islands, known as the Diaoyu Islands in China and the Tiaoyutai Islands in Taiwan, are a group of uninhabited islands in the East China Sea, administered by Japan. They were historically known in the Western world as the Pinnacle ...
.
The biggest warships in Japan's fleet since
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, "raised eyebrows in
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
and elsewhere because it bears a strong resemblance to a conventional aircraft carrier"
and has been described by the Chinese as an "aircraft-carrier in disguise."
Though called a destroyer, provisions aboard the vessels indicated that the ships could be used in the future to launch fighter jets (
F-35B) or other fixed wing
VTOL
A vertical take-off and landing (VTOL) aircraft is one that can takeoff and landing, take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust- ...
aircraft.
Japanese military sources confirmed that the possibility of operating fixed wing aircraft was incorporated into the design of the ships from the earliest stages of the ''Izumo'' program, but this was not made public yet at that moment. The aircraft elevators and the deck paint were designed to handle aircraft like the F-35B, and it would be possible to add a
ski-jump to the flight deck for
STOVL
A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically if it does not have a heavy payload) and land vertically (i.e. with no runway). The ...
operations.
In December 2017, several sources including ''
Reuters
Reuters ( ) is a news agency owned by Thomson Reuters. It employs around 2,500 journalists and 600 photojournalists in about 200 locations worldwide writing in 16 languages. Reuters is one of the largest news agencies in the world.
The agency ...
'' and ''
Yomiuri Shimbun
The is a Japanese newspaper published in Tokyo, Osaka, Fukuoka, Fukuoka, Fukuoka, and other major Japanese cities. It is one of the five major newspapers in Japan; the other four are ''The Asahi Shimbun'', the ''Chunichi Shimbun'', the ''Ma ...
'' reported that the Japanese government was contemplating modifying the ''Izumo'' class to operate F-35B STOVL aircraft. Multiple plans were reportedly under consideration, some of which call for
US Marine Corps F-35s to use the vessels while others for Japan to procure its own aircraft. The plan quickly raised criticism from China, where government officials reacted negatively and urged Japan to "act cautiously".
Later, in February 2018, the ''Yomiuri Shimbun'' reported that Japan was planning to acquire 40 F-35Bs, the Short Take-off and Vertical Landing (STOVL) variant of the Lockheed Martin Lightning II Joint Strike Fighter (JSF), which could be operated from the ''Izumo'' class with some modifications to the ships. It was estimated that each ''Izumo''-class carrier could operate 12 or more F-35B aircraft. In March that same year, the ruling
Liberal Democratic Party called upon the Japanese government to develop its own aircraft carriers and operate F-35B aircraft, which has been thought to include refitting the ''Izumo'' class. Defense Minister
Takeshi Iwaya announced on 27 November 2018 that Japan is considering buying F-35Bs within an order for an additional 100 F-35 aircraft, and as a consequence modifying both ''Izumo''-class helicopter carriers to operate F-35B were also considered.
Approval of conversion

On 18 December 2018, the Japanese Cabinet gave approval to modify the ''Izumo'' class into de facto
aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and hangar facilities for supporting, arming, deploying and recovering carrier-based aircraft, shipborne aircraft. Typically it is the ...
s.
The modifications will reinforce the decks of the ''Izumo''-class ships to support the additional weight of F-35B, as well as the heat and forces from the jets during vertical landing.
Each vessel will also have the bow section of its flight deck, which is currently trapezoidal, modified into a square shape. The ruling parties re-designated the ''Izumo''-class ships to multi-purpose operation destroyers.
On 30 December 2019, Japanese Ministry of Defense approved the FY2020 budget that would finance the refurbishment of the ''Izumo'' class for F-35B operation.
The
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the maritime land force service branch of the United States Department of Defense. It is responsible for conducting expeditionar ...
plans to operate their own STOVL F-35s from ''Izumo''-class ships in cooperation with the ship's crew to build up a Japanese capability to operate this type of aircraft. The Japan Air Self-Defense Force has ordered 42 STOVL F-35Bs in 2019 and will operate them from land bases once delivered. In July 2021 it was indicated that of the 42 F-35B variants to be acquired, 18 will be introduced by FY2023, six in FY2024 and two in FY2025. These are to form a single squadron consisting of about 20 aircraft operating from the
Nyutabaru Air Base in
Miyazaki Prefecture
is a Prefectures of Japan, prefecture of Japan located on the island of Kyūshū. Miyazaki Prefecture has a population of 1,028,215 as of 1 January 2025 and has a geographic area of 7,735 Square kilometre, km2 (2,986 sq mi). Miyazaki Prefectur ...
in southwestern Japan. The base is located in close proximity to the JMSDF's Kure Base in
Hiroshima Prefecture, which is the home port of JS ''Kaga''.
''
The Asahi Shimbun
is a Japanese daily newspaper founded in 1879. It is one of the oldest newspapers in Japan and Asia, and is considered a newspaper of record for Japan.
The ''Asahi Shimbun'' is one of the five largest newspapers in Japan along with the ''Yom ...
'' quotes
Japan's Defense Minister Takeshi Iwaya "The Izumo-class aircraft carrier role is to strengthen the air defense in the Pacific Ocean and to ensure the safety of the Self-Defense Force pilots." He also states, "there may be no runway available for the US aircraft in an emergency. I cannot say that the US F-35B should never be placed on an
MSDFescort vessel."
In 2020, ''Izumo'' began the conversion process. Initial modifications include strengthening the heat resistance of the deck and installing power supply equipment to enable the departure and arrival of the F-35B. A second renovation, to change the bow shape to a quadrangle for the safe operation of the F-35B the maintenance of the interior compartments, is scheduled to be carried out starting from the end of 2024 and be completed by the end of Fiscal Year 2026.
''Kaga'' began her initial modifications in March 2022 at the Japan Marine United (JMU) shipyard in
Kure, Hiroshima Prefecture. The proposed modification of ''Kaga'' will be more extensive (and significantly more expensive) and includes changes to the shape of the bow. The initial modification of ''Kaga'' was completed in early 2024 and is to be followed by a second modification of the ship’s interior, which is expected to begin in late 2026 and be completed by the end of Fiscal Year 2027.
On 3 October 2021, two USMC F-35Bs performed the first vertical landings and horizontal take-offs from JS ''Izumo'', marking the first time in more than 75 years that a fixed-wing aircraft operated from a Japanese carrier.
On 13 September 2023, ''Kaga'', which is undergoing initial modification, began a test voyage. For the first time, the ship showed its 'carrier-ised' appearance, with the bow changed to a rectangular shape and a sign painted on the deck for landing and taking off aircraft.
See also
*
Sea Control Ship
References
Bibliography
*
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External links
CG Photos of 19500t class 22DDH destroyerShips of the World
{{Combatant ship classes of the Japan Maritime Self-Defense Force
Helicopter carrier classes