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)