Both schools decide to have a test run of sorts, having the girls from the all-girls school stay at Kanenone for a month, in order to see how the boys and girls get along. Yuusuke Takazaki, the main character, has his hands full with his "perverted" roommates, nicknamed the Baka ("Idiot") Trio. The Baka Trio - which consists of Bacchi-Gū, an overweight shameless pervert, Ichiban-Boshi, a self-proclaimed ladies man, and Tenjin, a gentle giant who has a "little sister" fetish - are incredibly excited that there will be girls around.