Koguma, a shy 2nd-year student in high school with no parents, no money, no friends, and no goals for the future decides one day to shop for a motorbike. When she buys an inexpensive used Honda Super Cub, it leads to events that will change her life.

As Koguma slowly adjusts to life with her Cub, she mentions to Reiko that her luggage case seems convenient, so Reiko makes a call. After school, the pair visit a credit union, where the manager has an old Cub with a luggage case available to them.

The girls pack up and depart on a road trip to Kyushu, the most distant location their Cubs will take them, in order to shake off their winter doldrums and embrace spring. Along the way, Shii finds what she needs to help her continue her café project.