Shinobi Kid II: Kagemaru

Boss Sato is the client of Kagemaru's home clan, Nankotsu, and he's just making sure Kage is trained well enough for the important mission where he'd have to sneak into the enemy's house through a sophisticated ventilation tunnel and open the door from the inside for Sato's men.

Actually Sato was pretty satisfied with Kagemaru after a couple of simple tests, but he felt like playing with Kage's flexibility a little more because it was so much fun ^^;