Kousaka Yuzuna

The eldest sister she's Onii-chan's younger twin sister. The two of them attend the same class in school. She won't admit that she has a crush on her brother and makes excuses about why she wants to stay with him.

She has the mysterious power to telepathically send her thoughts to her brother.

With the secret underwear patch she wears a corset, cupless bra, and crotchless panties.