Koibito Swap

Midorikawa realizes after many years that he has feelings for his childhood friend, Kayo Yoshioka. After confessing to Yoshioka, she gave the impression that she also had feelings for him so they became lovers. However, one day he encounters Yoshioka having an affair with another man! This man appears in front of Midorikawa who has lost all hope.. This is a coming-of-age romantic comedy about revenge.

(Source: natalie, translated)