Japan is shaken by the sudden appearance of "Kaijuu." In the countryside, where there is a shortage of hands, a high school "Kaijuu Club" is mobilized for extermination. Tae Danjou, a first-year high school student, is devastated by the retirement of her favorite idol. Appearing before her is Utako-senpai, who protects the town with her magnificent red hair fluttering. "I'll never do 'oshi-katsu' (idol support) again," she had vowed, but... why can't she take her eyes off that figure! Defeat the Kaijuu! Shine, youth! Support your fave while you still can!! The Oshi-katsu Kaijuu youth romance begins now!!