Naoe Saki

Yamato's mother and former biker. She takes a subservient tone with her husband when they are alone, referring to him as "Master".

Spoiler

In Margit's route it is confirmed she's Kagekiyo sexual slave.

She's very doting towards Yamato and is the type of mother that always see her child as a little kid, in some routes she even feels sad when Yamato "leaves the nest". Got Yamato into raising hermit crabs.