ef ~ A Tale of Melodies

Story

In a story set years in the past, Himura Yuu is a studious and diligent young man intent solely on maintaining his top academic position at Otowa Academy. One day, he meets a mysterious girl named Amamiya Yuuko, who, to his surprise, recognizes him. Memories of a distant childhood, memories rather left forgotten...meeting Yuuko again will force Yuu to confront the regrets and sorrows of their collective pasts and presents. In the present, Kuze Shuuichi may seem like a womanizer, but upon closer inspection, is a man who would rather be left alone.

Synopsis via AniList (English).