Is Stringendo: Angel-tachi no Private Lesson hentai?
English title: Stringendo
Yes
Rated Rx (Hentai) on MyAnimeList.

OVA · 2006 · 12 episodes · Rx - Hentai
Hentai
Story about how each popular girls in high school ended up having sex with some of the less popular guys. Each of them have their own temptation for desire and lust which they could not control - that is Sex. (Source: ANN)
View on MyAnimeListShare
Check another title