Kirishima, Shirou (age 24) was suddenly downsized from work and his girlfriend dumped him! When he was complaining to his friend at a bar, a mysterious, beautiful, big breasted woman named Ishimura Ai asks him if he would like to work for her!

While drunk he ended up signing a contract with her. But the next day when he went to her place, and she walks out naked! He found out the truth about the contract. It wasn't a work contract but a marriage registration form. This is the story about a full-time house-husband!