Both of Us, Back in the Day (Ano Koro wa, Futaritomo, あのころは, ふたりとも) is the sixth episode of the Heya CampΔ anime.
Aoi discusses an igloo she made when she was younger, and the topic turns to her meeting Chiaki in middle school.
Continuing the stamp rally, they mention the Nanbu Fire Festival held every summer. Aoi and Chiaki remember their attendance, and how they spoke to one another at this event.
Chiaki recalls how she won a vending machine prize before sharing with Aoi.