Three years ago, a Maritime Self-Defense Force submarine collided with a cargo ship while surfacing off the coast of Kochi Prefecture. The then-captain's pay was cut due to inadequate command and supervision on board.

Five people were given disciplinary action. In February 2021, the submarine Soryu, which was training off the. coast of Cape Ashizuri in Kochiprefecture, collided. with a civilian cargo ship as it surfaced, injuring three submariners. The submarine was repaired at a cost of approximately 2.6 billion yen.