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.

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.

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.