A senior who's considered to be "perfect" attends the protagonist's university. People call him "Asagi-senpai." He enrolled some time after entering the workforce, so he's a little older than other students. He's kind and thoughtful to everyone. A senior dotted with a beautiful heart and body. While he's gentle, he also appears to be somewhat detached from those around him and his private life is shrouded in mystery.
The protagonist, Sachi, has never been in love but has an endless array of sexual partners. This self-proclaimed "slut", ends up falling in love with Asagi as she gets bored of her current sex life. Urged by her newfound romantic feelings, the protagonist approaches the mysterious "Asagi-senpai" to ascertain his true self.

There is a TL and R18 version.

Official Translations:
English, S.Chinese, T.Chinese, Korean