Kai and friends decide the only way they can get strong enough to defeat the Quatre Knights is through intensive training... but who is both strong enough, available, and willing to train them? Leon Souryu! So they travel to Leon`s isolated island, where an important lesson is waiting for Ishida.

Ishida discovers the gateway to the Quatre Knights` base... which means Aichi must be there! Although it may be a trap, Ishida and the gang step right up... and learn more of Aichi`s circumstances as well as the serious consequences of losing a fight in their "sanctuary"!