"The room you can't leave until you have sex" started out as a Twitter meme that ended up inspiring a lot of art and doujinshi over the years. The premise speaks for itself, it's an escape room/death game sort of situation, but with sex instead of killing and usually involving characters from anime/manga/games. Basically, the frustration of fans shouting "Just fuck already!" whenever something keeps the relationship between two characters ambiguous, taken to its logical extreme.