Sawatori Yukito had been looking for a job for a long time and one day saw an ad in the newspaper. It talked about a good reward for his work, and the guy decided to take a chance. He contacted his employer and agreed to become a servant in the same household.

Hentai tells the story of the relationship between Nanase's sisters Miku and Arisa. They have attractive looks and high intelligence, and are the idols of their school. That is why many young people are jealous of Sosuke-kun, the main character, since the sisters moved to live in the same house with him.