Hatsukoi no Osananajimi ga Otoko datta Hanashi.

Our MC is happily waiting for his childhood crush and friend as they meet up again after many years has passed. Little did he know that his childhood friend was never a girl, but a boy. What's worst is that his friend spotted them together and thinks that his childhood friend was mc's girlfriend. Now forced to go on a double date, mc has no choice but to follow through his plans to make his childhood friend pretend to be his girlfriend. Now go read it for yourselves cause I think im about to tell the whole story here.