花火与幽灵少女 - Hanabi and Ghost girl

Auto-translated A remote mountain town amid cicada sounds, peaceful on the surface but harboring a centuries-old dark secret. Protagonist Yuki Hanabi came to Sorei Town with her parents years ago; after their accident, her introverted nature led to her being ostracized. Now she lives alone in town, until she encounters the 'ghost' of someone already dead in an old school building.