Mihoshi has been bothering Saku too much lately so he takes a break from the club and goes to the library where he meets the student council president Fumie Kotozuka by chance. After talking with her, Saku realizes Mihoshi is merely expressing her feelings honestly like she always has and Saku agrees to accompany her with stargazing. However, the rainy season begins causing Mihoshi to get very depressed over the cloudy skies. With Saku's suggestion, the astronomy club goes to the planetarium and are shown the summer constellations. After the rain ends, Mihoshi wants the club to go on a summer stargazing camp.

Mihoshi and the other members are excited about the Autumn Stargazing Conference, and are surprised at the size of Nogishiro High School along with the number of members in their astronomy club. After the sun sets, everyone splits into groups and the process is explained by Nogishiro's astronomy club president Ayumi Ōmi; each group is free to stargaze until the moon sets, upon which each group will begin counting visible stars in a patch of sky to measure the overall brightness of the sky. Ayumi asks Saku to help on patrol around the school and they come across Hime and a second-year named Musa after she overreacts and thought he was trying to assault her. Afterwards, everyone goes back to the roof now that the moon has has set, and Ayumi confesses to Saku that her astronomy club actually only has nine members in it and mostly everyone else is from other clubs. Takeyasu Roma does a narration of the autumn sky myth which everyone loves. Ayumi later confronts Roma and reminds him that they were once members of the same astronomy club at Goshima Science Museum.