The Japanese navy introduced curry as a regular dish. Later, the army did the same. Together, they exposed many young men from all over Japan to curry, and it became a national dish. China did not have such institutional exposure to the dish.

For more on this, see https://www.reddit.com/r/AskHistorians/comments/b223ix/how_and_when_did_curry_become_a_part_of_japanese/