What does the word "jiken" on young Luffy's shirt mean in Japanese? In One Piece manga, young Luffy wears a shirt containing the word "jiken".



What does "jiken" mean in Japanese?
In this context, jiken (事件) means "incident" or "case".

The full picture indicates tamago jiken which literally means "the egg incident" where a chick is killed due to the egg getting cracked.

There might not be any deeper meaning considering Oda's nature of humor.