Shinai naru Tomo e Sasagu Noroi

Hironobu and Taro were the best of friends in high school, but after Hironobu rejects Taro's kiss, the two fall apart.

Three years after graduation, Hironobu finds himself unable to find a girlfriend because of memories of Taro and calls it "Taro's Curse." While desperately trying to move on, he runs into Taro and is confused when the latter acts like nothing has happened between the two.

(Source: Ichijinsha, translated)