Ai wa Kagi no Kazu Dake

“Love Is A Number Of Keys” is a story about Jyun; living alone for the first time and becoming an assistant apartment manager. He soon finds out, by being a peeping tom mind you, that this particular apartment services sex to people. The ladies do this out of enjoyment, and Sumire (senior manager and A-class sex fiend herself) trusts him with this secret!