Papa Be in Love with You.

Tomoya has been bullied since he was little. The only one who protected Tomoya was a good-looking and gentle childhood friend, Kouhei. They reunited for the first time in a few years, and unexpectedly, Kouhei already became the daddy of a child! Tomoya couldn't hide his shock, but he was unable to refuse if Kouhei asked for his help, who struggles to raise a child as a single parent. (Source: Sankosha, translated)