Naoe Kagekiyo

Yamato's father. Taught Yamato quite a few tricks. After giving up on Japan, he and his wife went to Europe to work as "merchants", buying and dealing with companies in/close to bankruptcy. Sometimes their deals are called "suspicious", but its probably because Kagekiyo's tactics to trick his targets and sometimes he seems cold to even his family.

Spoiler

In Margit's route Kagekiyo says to Yamato he made Saki his by "Showing his true feelings by fucking her" and has a master/slave relationship much stronger than Yamato in any route.

Despite all this, his love towards Saki and Yamato is real, and strong.