Ai wa Kagi no Kazu dake... Fuuzoku Mansion
English title: Love is the Number of Keys
Japanese title: 愛は鍵の数だけ… 風俗マンション
Alternative titles: Ai ha Kagi no Kazu dake... Fuuzoku Mansion, Love is the Number of Keys
Type: OVA
Source: Original
Episodes: 1
Status: Finished Airing
Aired: May 25, 2002
Duration: 28 min
Rating: Rx - Hentai
Studios: Concept Films
Producers: Milky Animation Label
Licensors: NuTech Digital
Genres: Hentai

Jun is on his own for the first time, as his father has gone overseas for a new job. He stays behind because of schooling and moves into an apartment complex as an assistant manager, only to discover that the place is a sex service apartment.