Yonji Vinsmoke, also known as 'Winch Green', is the fourth son of the Vinsmoke Family and a prince of the Germa 66 army in the anime and manga series One Piece. He is Sanji's younger brother and is known for his arrogance and immense physical strength, a result of genetic modifications. Yonji plays a supporting antagonist role during the Whole Cake Island Arc, where he and his siblings are involved in Big Mom's plot to form an alliance with the Vinsmoke family through marriage.