S1·E10 Enter the Ninja Fighter

Kamui and Kai advance to the second round of the tournament, along with Ninja Master M, an eccentric player who dresses and acts like a ninja. He meets Aichi, who deduces that he is actually his teacher Mark Whiting, but he denies that claim (even though it's true). The tournament progresses to the second round matches with Aichi facing off against Ninja Master M while Kai plays against the previous tournament's champion Kazuki Inaba.

Ninja Master M uses his Nubatama ninja units' effects to deplete the cards in Aichi's hands. He drives Aichi to a corner when he rides his ace card Stealth Dragon Voidmaster and leaves only one card in Aichi's hand. While this is going on, Kai defeats Inaba in his match.