One Piece Characters in One Piece Merch. We make life easier for you with One Piece merch. Everything is on point and of quality material that you can use as a gift or to decorate your own room! One Piece is a long-running shonen manga series written and illustrated by Eiichiro Oda. It has been serialized in Shueisha's Weekly Shonen Jump magazine since September 2, 1997. The story focuses on Monkey D. Luffy, a young boy who ends up on a journey to become King of the Pirates after accidentally eating a devil fruit (a type of fruit that grants its eater superhuman abilities in return for being unable to eat anything else).