Love is the Number of Keys

Ai wa Kagi no Kazu dake... Fuuzoku Mansion | Ai wa Kagi no Kazu Dake | Ai wa Kagi no Kazu dake

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.