Hyung's Omega

Su-A and Do-Yoon have been friends since childhood, which has made it incredibly difficult for Do-Yoon who's now been swept up in his friend's heat cycle. The two end up falling into a relationship, but can Do-Yoon keep up with his now-lover's intense cycle? Or are the two doomed to burn out and become estranged? (Source: Tapas) Note: Includes 13 extra chapters.