Kuro Gal ni Natta kara Shinyuu to shitemita.
English title: Seduced by My Best Friend
Japanese title: 黒ギャルになったから親友としてみた。
Type: ONA
Episodes: 8
Source: Manga
Genres: Boys Love, Hentai
Studios: Elias
Producers: Suiseisha, blackflag
Duration: 6 min per ep
Rating: Rx - Hentai

Shion and Rui are the dream team when it comes to hitting on women. Tonight was going to be another night of hooking up with girls for Shion, but he ended up taking a strange drug. When he woke up... he'd turned into a girl?! Rui came looking for Shion, but didn't recognize him, and started hitting on him...

(Source: Suiseisha, translated)