Osananananajimi

A brief description of the Manga Osananananajimi:

Yuuichi Momose and Sumi Fujino have been friends since childhood, growing up together. Now in high school, their relationship has become more distant since entering adolescence. While they still understand each other deeply, an awkward formality lingers between them. This fragile dynamic shifts unexpectedly when Sumi shows up at Yuuichi’s house one day…?