The line comes from One Piece, Eiichiro Oda's long-running manga and anime about Monkey D. Luffy and his Straw Hat crew searching for the legendary treasure known as the One Piece. Becoming King of the Pirates is Luffy's defining goal, and he states it in Japanese as 'Kaizoku ou ni ore wa naru' throughout the series, which began as a manga in 1997 and as an anime in 1999. Fans have clipped the declaration for edits, memes and motivational videos for years because it sums up the entire story in a single confident shout.