Conquering One Piece with a Spirit Weapon

A boy who has never watched One Piece accidentally transmigrates from a world of magic to the world of One Piece. Along with awakening his magic, he gains control over spirit weapons that can grant people supernatural abilities and even transform into beautiful young women. Monkey D. Luffy, who dreams of becoming the Pirate King, takes an interest in him and persuades him to become his first mate. When two chuuni souls collide, the Straw Hat Pirates earn their legendary reputation. (This is a story about growing stronger alongside the crew!)