When Hideyoshi's tone-deaf twin is asked to sing the school song, he's roped into a costume change that's just asking for trouble. Then, Akihisa gets a new admirer--or two?--when he risks his neck to help Haduki cheer up her big sis.
Complications arise after Mizuki and Shouko interrupt Akihisa's card game. Later, during a test of the Avatar system, the summoners of Class F are embarrassed to find their innermost thoughts revealed.
After Akihisa seeks Kouta's advice on how to deal with a troubling blackmail note, he learns that Yuuji is in a similar situation. Kouta's investigation uncovers clues that suggest one person is causing all of the problems.
The search for the blackmailer continues, with Akihisa, Yuuji and the others narrowing in on a suspect: Aiko Kudou. In order to confirm their hunch, the gang once again sets out to sneak a peek during bath time.
The guys rally every male at camp to assist in their mission of peeping on the girls. After combining their abilities, they finally make it to the girls' restroom - only to see something none of them expected!
When Class F is challenged by some older students, the battle takes place in a haunted house. To win, Class F must get through without screaming. Unfortunately, the older kids have some scary tricks up their sleeves.