The Japan Maritime Self-Defense Force (海上自衛隊, Kaijou Jieitai, abbreviated as Kaiji or JMSDF) is the naval branch of the Japan Self-Defense Force. It is the modern successor to the Imperial Japanese Navy, a position it shares with the Japan Coast Guard.
As it is officially a self-defense force, not a military navy, almost all of the JMSDF's large surface ships are called 護衛艦 (goei-kan, lit. "guard ship" or "escort ship") and officially classed as destroyers. However, the term does not include submarines, mine warfare vessels, variants of patrol boat, landing & transport vessels and training ships. The fact that Izumo-class helicopter carriers with a displacement of nearly 20,000 tons are called "destroyers" is often the butt of jokes.
Unlike the Japan Ground Self-Defense Force, which dropped most traditions associated with the Imperial Japanese Army, the JMSDF still maintains many traditions of its predecessor, the Imperial Japanese Navy. For example, their tradition of eating curry rice for lunch every weekend was handed down from the IJN.
