List of active Japan Maritime Self-Defense Force ships

Authorized projects for the Japanese Maritime Self-Defense Force include the ongoing construction of an improved AIP-type non-nuclear attack submarine class, the recapitalization of the JMSDF's frigate fleet units, and the acquisition of a pair of JMSDF-owned oil tankers and up to four amphibious transports, as well as the pending construction of a dozen next-generation offshore patrol vessels (OPV) and two "Aegis system equipped ships" (ASEV) to provide dedicated sea-based ballistic missile defense (BMD) coverage of the Japanese home islands to replace the cancelled Aegis Ashore land-based BMD system.

[62] In August 2017, the Acquisition, Technology & Logistics Agency (ATLA) selected Mitsubishi Heavy Industries (MHI) and Mitsui Engineering and Shipbuilding (MES) as the prime contractor and subcontractor to construct the frigate.

[63] At a press conference held on February 16, 2021, Defense Minister Nobuo Kishi announced that the Japan Self-Defense Force (JSDF) established a joint amphibious unit equipped with three new transport ships by 2024.

[66] On 30 June 2022, the Japan Ministry of Defense (MOD) announced the construction of 12 offshore patrol vessels (OPV) (pictured) for the Japanese Maritime Self-Defense Force (JMSDF) at a cost of ¥ 9 billion (US$66 million) per ship.

Japan Marine United Corporation (JMU) is the prime contractor for this program with Mitsubishi Heavy Industries (MHI) chosen to be the subcontractor.

[67][68] Given the various maritime-related territorial disputes and expanding operational requirements (pictured), the Japanese Maritime Self-Defense (JMSDF) has shown increased interest in augmenting its amphibious lift and expeditionary capabilities.

Consequently, several Japanese defense firms such as Japan Marine United Corporation (JMU) and Mitsui Engineering & Shipbuilding (MES) have proposed amphibious warfare options at such industry trade shows as the Maritime Air Systems & Technologies (MAST) and Defence and Security Equipment International (DSEI) exhibits.

Also, on March 4, 2014, Japan and the United States announced a bilateral research project on a LCS-style warship pursuant to the Mutual Defense Assistance Act.

The vessel's design features a floodable well deck for embarking two LCAC air-cushion landing craft plus 20 AAV7A1 amphibious assault vehicles.

The JMU concept art displayed three RIM-116 Rolling Airframe Missile (RAM) SeaRAM launchers located before and aft of the ship's island superstructure, as well as a Mk 15 Phalanx 20mm-Vulcan cannon-armed Close-in Weapon System (CIWS) on the forward deck.

[72] A JMU representative told Jane's 360 that while the Japan Maritime Self-Defense Force did not have a current requirement for an LHD-type amphibious assault ship of any kind to join the JMSDF's Self Defense Fleet, the Japan Marine United Corporation still expected the JMSDF to eventually issue such a requirement in the near future, with the JMU design as an alternative to a foreign design.

MES drew on its experience from constructing and delivering the Osumi and Shimokita tank landing ships (LSTs) to the JMSDF when designing the new LHD.

[74] Mitsui's proposed LHD vessel is designed for large-scale transportation of Landing Craft Air Cushion (LCAC) hovercraft, main battle tanks (MBTs), vehicles, cargo, and equipment, with multi-mission features.

[74] At the Maritime Air Systems & Technologies (MAST) 2017 naval defense exhibition held in Tokyo, Mitsui Engineering & Shipbuilding (MES) unveiled a new amphibious transport dock (LPD) concept.

[75] At the Maritime Air Systems & Technologies (MAST) 2017 naval defense exhibition held in Tokyo, Mitsui Engineering & Shipbuilding (MES) unveiled its Mobile Landing Platform (MLP) concept designed for large scale transportation of Landing Craft Air Cushion (LCAC) hovercraft, main battle tanks (MBTs), vehicles, cargo, and other equipment, with multi-mission and modular features.

[77][78] The joint HSMVO research is conducted by the Acquisition, Technology & Logistics Agency (ATLA) and the Naval Surface Warfare Center Carderock Division of the US Navy.

The mission capabilities of the concept includes mine countermeasure (MCM), humanitarian assistance and disaster recover (HADR), and offshore patrol/special ops.