Reiji Sakamaki

Reiji is the 2nd son in the family.
He is a very strict type.
Reiji is the one who takes care of the household and of all his younger brothers while Shuu, who is the one supposed to be doing this, slack off.
Because of Shuu's lazy behaviour, Reiji hates him and is jealous of his position of eldest son of the family as Shuu gets all the attention.
Even though he's usually gentle, he insults Yui terribly, yet he's also a sadist vampire.