Yui Shiromaru

Birthday: April 6

Yui Shiromaru is Nakami and Isaki's senpai. She is the last member of the previous astronomy club before it got dissolved and the winner in a national high school astrophotography competition.

She owns and manages an arcade called "Betty" and lives right next to it in a modest unit.

Yui has a cousin named Kai.

(Source: Wikipedia, translated)