Nao is a girl who lives in a small rural town in the mountains. With Hiroki, a somewhat unreliable childhood friend who has been with her ever since she was a child, taking care of her, she is peacefully spending her remaining days as a student as her high school graduation approaches. Hiroki's father, Masaki, watches over them kindly. He has been raising Hiroki single-handedly since his wife died of illness almost as soon as Hiroki was born. Nao wants to help Masaki, so she goes to Hiroki and Masaki's house every morning and helps out at her house, and adores Masaki like her real father. On the day of Hiroki's high school graduation, he decides to finally confess his feelings to Nao, who he has been in love with for many years. However, after the graduation ceremony, another childhood friend, Sayuki, stopped Hiroki.
Sayuki had decided to move to Tokyo alone to attend university, but she brings Hiroki to her home to listen to her worries.