There is a tiny leader on Wolverine’s forehead sitting on a stool and commanding his troops to invade Wolverine’s brain. These tiny soldiers are going to invade Wolverine’s body in an attempt to destroy him. The leader himself isn’t going to invade Wolverine’s brain, he’s just going to sit on the stool and supervise.
Soon they realize that they cannot invade Wolverine through his head so they travel down to his leg and try to enter through his shin (しん). The little soldiers take a big knife and slice open Wolverine’s shin in order to invade his body.