The Earth's Secret Weapon! (地球軍、最後の秘密兵器！！, Chikyūgun, Saigo no Himitsu Heiki!!; lit. "The Earth Army's Last Secret Weapon!!") is the four hundred eighty-first chapter of the Dragon Ball manga.
Mr. Satan arrives at Majin Buu's house. He confronts Majin Buu and tries to defeat him, but it fails. Buu finds him funny. This is the start of their friendship.