Hoshizora no Memoria: Wish Upon A Shooting Star

The story begins with the protagonist, Kogasaka You, and his younger sister Chinami moving back to their hometown of Hibarigasaki. After living for several years in a city, their mother had died, and they returned to Hibarigaski to live with their aunt Shino. The game switches to a view of the past, where every day after school during the month before he left, You would go to the lookout and play with a girl, his first ever friend. (wikipedia.org)