Suki to Ittara, Kimi wa

Tomoyuki attends the wedding of Shintarou, a friend from high school he's secretly been in love with for years. On his way home, trying to drown the pain of heartbreak with too much alcohol, he stops by a park where he meets a mysterious handsome man named Haru. Haru, who says someone canceled on him at the last minute, suddenly asks, "Go on a date with me"...-

(Source: Dogenzaka Shobo, translated)

Note: Includes one extra chapter.