The older brother of
Ena and a virgin who get conscious of his little sister. He really hates when she brings men in her room because he can heard her moaning behind the thin wall who separates there rooms.
Even if he isn't a huge siscon, he often masturbates by fantasizing about Ena or while she is with a boy. He is envious of her success. He thinks that Ena is the complete opposite of the "ideal sister type" you can see in anime or manga even if he thinks she's cute.
He hates that his sister is a bitch, and they do not get along well because of that. He often calls her "bitch" in his mind.
(spoiler hidden)