The Yubari-class destroyer escort (or frigate

Frigate

A frigate is any of several types of warship, the term having been used for ships of various sizes and roles over the last few centuries.In the 17th century, the term was used for any warship built for speed and maneuverability, the description often used being "frigate-built"...

) of the Japanese Maritime Self-Defense Force is the successor of the Ishikari-class destroyer escort

Destroyer escort

A destroyer escort is the classification for a smaller, lightly armed warship designed to be used to escort convoys of merchant marine ships, primarily of the United States Merchant Marine in World War II. It is employed primarily for anti-submarine warfare, but also provides some protection...

. Yubari was named after the experimental light cruiser of the 1920s-30s, which served in (and was lost during) World War II.

This class was the extended version of its predecessor, JDS Ishikari (DE-226). The displacement was slightly increased, and some improvements were introduced. But they were almost same and there were many points in common as follows:
The CODOG propulsion system.

The propulsion system of this class was identical with the one of its predecessor. The Rolls-Royce Olympus

Rolls-Royce Olympus

The Rolls-Royce Olympus was one of the world's first two-spool axial-flow turbojet aircraft engines, originally developed and produced by Bristol Aero Engines. First running in 1950, its initial use was as the powerplant of the Avro Vulcan V Bomber...

 TM-3B manufactured by the Kawasaki Heavy Industries

Kawasaki Heavy Industries

is an international corporation based in Japan. It has headquarters in both Chūō-ku, Kobe and Minato, Tokyo.The company is named after its founder Shōzō Kawasaki and has no connection with the city of Kawasaki, Kanagawa....

 under license was used for boosting. The cruising engine is the Kawaksaki 6DRV 35/44 diesel engine developed by the Technical Research and Development Institute (TRDI).

Centre-superstructure style.

Whereas the JMSDF incline to adopt the flush decker style, in this class, the superstructure is at the center of the ship to save the space of the ship. This was very controversial decision, and because of this decision, there has been the criticism about the ocean going capability of this class.

Simplified but sufficient C4ISR system.

This class was not equipped with air-search radar whereas her predecessors almost had. Alternatively there were the OPS-28 surface search and target acquisition radar which can deal with low-altitude aircraft and missiles. And also the FCS-2 gun fire-control system has the air-searching capability. As the tactical data processing system, they has the OYQ-5 being capable of receiving data automatically from other ships via Link-14 (STANAG 5514; the data link with the Radioteletype

Radioteletype

Radioteletype is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations, later superseded by personal computers running software to emulate teleprinters, connected by radio rather than a wired link.The term radioteletype is used to...

).

Brand-new weapon systems.

This class was equipped with eight Boeing Harpoon Surface-to-surface missile

Surface-to-surface missile

A surface-to-surface missile is a guided projectile launched from a hand-held, vehicle mounted, trailer mounted or fixed installation or from a ship. They are often powered by a rocket motor or sometimes fired by an explosive charge, since the launching platform is typically stationary or moving...

 as the key weapon system whereas traditional Japanese frigates weighed heavily on the Anti-submarine warfare

Anti-submarine warfare

Anti-submarine warfare is a branch of naval warfare that uses surface warships, aircraft, or other submarines to find, track and deter, damage or destroy enemy submarines....

. According to this mission concept, its predecessor's Mark 16 GMLS for the ASROC

ASROC

ASROC is an all-weather, all sea-conditions anti-submarine missile system. Developed by the United States Navy in the 1950s, it was deployed in the 1960s, updated in the 1990s, and eventually installed on over 200 USN surface ships, specifically cruisers, destroyers, and frigates...

 system was removed. And a modern Otobreda 76 mm

Otobreda 76 mm

The Otobreda 76 mm gun is a naval artillery piece built by the Italian defence conglomerate Otobreda. It is based on the Oto Melara 76mm/L62 Allargato, which was bigger and heavier...

 gun replaced its predecessor's older 3-inch gun and automation greatly reduced the number of crew needed. The Phalanx CIWS

Phalanx CIWS

The Phalanx CIWS is an anti-ship missile defense system. It is a close-in weapon system and was designed and manufactured by the General Dynamics Corporation, Pomona Division...

 placed in the stern area, although it was not installed after all.

All two ships of this class were deployed at the Ominato District Force (home-ported at Mutsu, Aomori

Mutsu, Aomori

is a city located in northeastern Aomori in the Tōhoku region of Japan. As of 2009, the city had an estimated population of 61,205 and a density of 70.09 persons per km²...

). The Ominato District is the northernmost district of the JMSDF and forefront against the Russian Pacific Fleet

Pacific Fleet (Russia)

The Pacific Fleet is the part of the Russian Navy that is stationed in the Pacific Ocean, which formerly secured the Far Eastern borders of the Soviet Union. The fleet headquarters is located at Vladivostok and a number of fleet bases are located in the Vladivostok area...

. But it was decided that even this class was too small to continue production, so it was succeeded by the with the entire new design.

Ships in the class

Pennant no.	Name	Laid down	Launched	Commissioned	Decommissioned	Home port
DE-227	Yubari	9 February 1981	22 February 1982	18 March 1983	25 June 2010	Ominato
DE-228	Yubetsu	14 January 1982	25 January 1983	14 February 1984	25 June 2010	Ominato