The high school student Kurashiki Midsummer has one of the best kendo skills in Japan, but she is not good at studying. Together with Tsumugi, an insect video distributor, and Ayano, an urban legend and conspiracy theorist, it was midsummer to receive repair from the first day of summer vacation, but at that time, a Self-Defense Force helicopter landed in the schoolyard. This was the beginning of the summer vacation which is super dangerous and too hot for midsummer!