Kokonotsu Shikada is the son of a dagashi snack shop owner. Although he wants to become a manga artist, his father, Yo, wants him to take over the family business. One day, a girl named Hotaru Shidare shows up at the shop and challenges Kokonotsu.

Hotaru tells Kokonotsu that Kinako-bou grabs her attention due to its plain packaging and lack of mascot characters, calling it a desert warrior. She also gives a lecture to Kokonotsu and Saya on the history of Fue Ramune.

Hotaru exacerbates the summer heat by turning off the shop's AC and boiling water to make Buta-men. Saya's suspicions are raised when Hotaru asks about her relationship with Kokonotsu.

Hotaru challenges Kokonotsu to compete in a blind fugashi taste test. She also helps him to run back to Café Endo when she realizes that he forgot something very important to him at the café.

Hotaru visits Shikada Dagashi after business hours to conduct a covert exchange with Kokonotsu’s father Yo. Later, she lets Kokonotsu and To in on her secret moneymaking technique.

Kokonotsu, To, and Saya visit the temple, where they find Hotaru behaving even more strangely than usual. On a separate occasion, Saya reminisces about playing with Kokonotsu when they were in the third grade.