Chiguhagu na Kiss

Third year Kumai wants to enjoy his final days of youth. He wants a girlfriend, but was never able to take the step forward due to past trauma. After hearing that a girl he was close with broke up with her boyfriend recently, he decides to contact her and they soon got together! Overjoyed to finally have a girlfriend, he goes to see her the next day...only to be met by Sasahara, the most handsome guy in his grade! This is a coming-of-age romance that begins over a misunderstanding between a super popular hottie and a pure late bloomer!

(Source: Shueisha, translated)