With the help of the feline science of the mysterious future cat Nuru, the five members of the Defense Club have become the "Hi-CARA Romantic Squad" and successfully defeated the monsters plotting to take over the Earth. Then, before them appears the "Ban-CARA Avant Guard Corps", an Earth Conquest Club led by the mysterious prairie dog Master Kyan. Their true identities are none other than Doumeki Straight, Nyutou Samon and Nekoma Tasuku, roommates at the Kurotama Dorm and members of the Binan High School Student Council. With lies and enemies under the same roof, it's impossible for something not to happen... right?

Once a month, Binan High School's Handsome Boys Contest is held as a regular event. Since entering the school, Sukayu Narushi has been winning the contest in a row, and is a beauty guru recognized by both himself and others.

For the dorm students who live away from their parents, the absence of their dorm breadwinner is a real crisis for their lives.

Summer vacation has begun at Binan High School, and Aso Sorata returns home with the gluttonous Oshamanbe, whom he caught with mountain delicacies. Waiting for them in their hometown are Aso's three younger brothers.