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.
Koguma rushes to the narrow dirt road on her Cub to find Shii, who is half-submerged in a freezing river. She takes her back to her apartment to warm her up and dry her out, but Shii soon reveals that she has other, deeper issues with the winter weather.
Shii invites Koguma and Reiko over to her family's shop for coffee, to allow her father to thank them for their help with the culture festival. The girls continue to look for ways to prepare for riding their Cubs during the upcoming winter months.
With the arrival of autumn, Koguma and Reiko's attention turns to getting ready for winter. When the class culture festival committee runs into a snag getting what they need for their activity, the pair volunteer to use their Cubs to come to the rescue.
Koguma visits Reiko at her home, and the two have dinner together. Reiko recounts the story of how she took a job at the Mountain Hut Kikuya over the summer as a means to pursue her own dream, something which proved to be more difficult than expected.
Koguma is a high school girl in Yamanashi. She has no parents, friends, or hobbies, and her daily life is empty. One day, Koguma gets a used Honda Super Cub motorcycle. This is her first time going to school on a motorcycle. Running out of gas and hitting detours become a small source of adventure in Koguma's life. She is satisfied with this strange transformation, but her classmate Reiko ends up talking to her about how she also goes to school by motorcycle. One Super Cub begins to open up a lonely girl's world, introducing her to a new everyday life and friendship.