While enjoying a carefree summer break, unexpectedly, Asahi Kirisaki gets informed that his grandmother has been admitted to hospital.
Because of the hospitalization, his grandmother's bathhouse is in danger of going out of business!
Asahi wants to do something about it, so he asks his older sister, Jun Kirisaki, for advice.
There, Jun asks whether he is absolutely serious about this.
"Of course I'm serious!"
Then, Jun hands a paper bag to Asahi.
Inside was a wig and a set of what appeared to be girls' clothes.