Kiryuu Yuzuha

She is three years older than the main character. She has always loved him dearly and kept in touch with him through letters and other correspondence while they were apart.

She never leaves the protagonist's side when he returns, and takes excessive care of him, such as sleeping with him and washing his back in the bathtub.

In fact, she is very possessive.

Spoiler

She killed her own father who attempted to rape her. She has always planned on giving her virginity to the protagonist and nothing will stop her in doing that.