Kuchibiru no Yukue

Yusuke and Soji have been close since junior high and are flirting with the notion of becoming a couple. But when Soji suddenly announces his intentions to marry, Yusuke is devastated. The friends part ways until three years later, when they meet by coincidence on a cigarette break. Still refusing to acknowledge his feelings, Soji faces the clash of his still-simmering love for Yusuke and his duty to his wife—even as Masahito, Soji's rival, begins to make a play for Yusuke's heart.

(Source: SuBLime)