Yuffie guessed right about Shinobu's lack of humor at this bewitching hour. The shinobi is known to be a bit stern at times. He's not the type to smile often nor is he easily amused by the jest of a teenage delinquent.

Her attack is easily parried by the sapphire blade Ame-no-Ohabari. Shinobu almost decided to keep his sword sheathed in fear accidentally injuring the girl. Yuffie might be his student for the evening but she's royalty. A tratior like him injuring the daimyo's daughter would surely not sit well with either acting Mizukages.

Shinobu probably would be executed on the spot.

"Decent technique." He compliments before quickly putting some distance between them. "But sloppy still."