Sex: Prologue
Japanese title: SEX～Prologue～
Type: OVA
Source: Manga
Episodes: 1
Status: Finished Airing
Aired: May 7, 2018
Duration: 1 min
Rating: PG-13 - Teens 13 or older
Studios: MAPPA
Producers: DMM pictures
Genres: Action, Drama
Themes: School
Demographics: Seinen

The anime depicts an original story before Kaho arrives, when Yuki and Natsu have just met in Okinawa.

(Source: ANN)

The promotional video is a home video exclusive. Customers must first purchase all four volumes of the Sex 30th Anniversary Edition manga volumes, take the tickets included in volumes 1-3 and send them with the postcard included with volume 4. The Blu-ray Disc will be sent to buyers in March 2018 so long as the postcard is postmarked before December 31. (Source: ANN)