Ookumo-Chan Flashback

Briefly about Ookumo-Chan Flashback manga:

This manga centers around first-year high school student Minoru Suzuki, who sometimes sees visions of his own mother's past as a high school student. Minoru learns of an incident that happened when his mother was in high school, involving her friend Sayuri and Sayuri's boyfriend Kento Yamada. He also learns of the events surrounding her friend Oumi Kanazawa, who died in an accident after attempting to save Sayuri from being hit by a truck.