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.

The new semester starts and on the bus to school Saku notices a tall man also getting off at the school. During the welcome back ceremony, the man that Saku saw earlier is introduced as a new teacher named Nozomu Soma who is in charge of Saku's class and world history. Mihoshi calls him "So-nii" in front of everyone and rumors abound as to what their relationship is. Later, Soma becomes the astronomy club's adviser and he explains to the others how Mihoshi's father was his professor at college and also the club adviser for their astronomy club. Soma wants the club to do a planetarium for the upcoming cultural festival and they get in the top three in a popularity contest in exhibits, the club will get more funding. Saku becomes annoyed at Mihoshi's and Soma's relationship and is approached by Fumie to help with the literature club.

After overhearing Mihoshi and Soma about plans together on the weekend, Saku, Hime and Edogawa follow them around town to find out what is going on, and initially they are out on a date. They eventually follow them to the grave site of Mihoshi's father who died in a car accident and everyone pays their respects. Saku, Hime and Edogawa feel awkward around Mihoshi after this. Fumie tries to give Saku a bookmark souvenir from her school trip to Hokkaido, but her glasses are broken after Saku protects her from a stray baseball. Saku offers to walks her home and on the way they run into two members of the literature club who to take her the rest of the way. Saku gets Fumie's help to set up a shooting star viewing event at school for Mihoshi, who is overcome with emotion over it.