When I woke up in the morning, I had become a girl, so I'll do my best as a girl for now.

Shikumo Sora, the protagonist, is a third-year student at Seishun Middle School. One morning when she wakes up, she finds that she no longer has a son and instead has two large mountains attached to her. In other words, she has become a girl. Sora, who is easygoing, accepts her new female form, thinking that what's done is done. This is a story of Sora growing up as a girl while experiencing various situations.