Kawazoko Gentou

Tadashi Endou has gone through a traumatic experience that's forced him to become a shut in. With walls lined end-to-end with mysterious photographs he cannot remember taking, the only person he really sees is his classmate Sumida, who shows up every day with class printouts. But as the mysteries behind Endou's life start to reach a breaking point, he learns that Sumida isn't an actual person in his class! What else will his recovered memories reveal and what will it mean for his life?

(Source: Irodori Comics)