The main character is a sophomore in high school. In the spring, the third-year seniors graduate, leaving him and his classmate, Hoshino Suna, alone.
Suna was never good at group activities.

She only joined the Astronomical Observation Club at the request of a senior member of the club she used to be in.

The protagonist, who loves the stars, did not want the club to be abolished, so he gathered the members by himself.

Seeing the protagonist, Suna starts to help him gather the members of the club.

[From Steam]