Baka Dakedo Chinchin Shaburu no Dake wa Jouzu na Chii-chan

In the heat of summer, a student who lives alone due to complicated circumstances with his family runs into a classmate at a convenience store. Her name is Shiinea Chieri, or Chii-chan, and she has large breasts, a nice figure, and is notably open about her sexuality and escapades. The chance of being with her seems slim... but then she smiles...