Based on the manga by Yuunagi Kaoru.

The main character, Yu, was at the depths of despair; he was dumped by his lover, and failed in the entrance exams. He moved to a new apartment to engage in studying for the entrance exam next year. However, he found that his new room was above an erotic night club. When he entered the room, there was a girl changing her clothes.

(Source: AnimeNfo)