First appearance - 39th episode when Nyankii went to America to meet them. Second (brief) appearance - in the end of 53th episode.
Himitsu Ninjatai Yankii include:
- Michael - leader of the team. He is Yattaro's counterpart. He uses Nyan-Nyan Magnum (Revolver) with pinpoint accuracy. Magnum can be used to perfom Kyattsu Ai Shuutingu - Michael's Hissatsu attack. He and Yattaro didn't see eye-to-eye at first but have soon learned to work together to save their comrades.
- Madonna - A tall and curvaceous she-cat who uses a whip. She is Pururun's counterpart and is arguably the more attractive one to Yattaro and Sukashii.
- Prince - A suave and agile cat. Weapon: rapier. He is Sukashii's counterpart. Unlike his counterpart, Prince is handsome, attractive, and more successful in romance as he is able to attract Pururun.