Co-Ed Affairs

Co-Ed Affairs (Kouin Tenshi: Haitoku no Riseennu) is a short Hentai OVA that is part of the "Vanilla Series".

Three students, Moemi, Reina and Mitsugu, begin to discover themselves sexually by filming a video of themselves, from inviting their neighbor to Moemi losing her virginity. Mitsugu herself is a lot more curious than Moemi and Reina who are a bit shy about themselves.

Tropes

 * Home Porn Movie: The setting of the entire plot of the story which plays out like a documentary in the beginning.