|Manga Debut||Chapter 23|
Kasao-kun is a magical weapon created by Jack.
Kasao-kun was created by Jack as a defense weapon to protect himself of Blue's attack. He again created him, when Keel attacked him with his tail. Unlucky for Jack, on of the bones in Kasao-kun was from Bone, who made a opening so that Mippy can enter and stab Jack.