Ai mo Kawarazu

Ai mo Kawarazu manga :

Takeru and Seiichirou are childhood friends. They grew apart over the years but have recently been meeting each other again. Takeru enjoys hanging out with Seiichirou just like when they were kids, but he learns that the same person has become infamous for being a huge playboy. He's perplexed, but more so when Seiichirou kissed and confessed to him while drunk.