Renai Hensachi Kaisouroku

While reminiscing about the good old days at a middle school reunion, Kusui is unable to stop thinking about his first love: his middle school boyfriend Chizuwa, a petite classmate with a shy smile. A special guest crashes the party, and this confident man in a suit turns out to be none other than Chizuwa, who's here to confront Kusui about the end of their relationship.

(Source: Kasakura Shuppansha, translated)