Dousei Ai (1996)

Blurb:
Tsubaki Sugiura, a normal 14-year-old, is thoroughly rejected by his trusted friend Kaoru Ebata. “There’s no way I’d fall in love with a guy!” With these words, Tsubaki’s heart is broken, and the darkness it holds starts to be revealed. Koutarou Takamura is a 14-year-old who excels at everything he does while pretending to be average. He always admired the virtue of his simple older brother. But, the intrusion of his brother’s girlfriend deprives him of their precious days together. “Is there no place that will accept me as I am? Where do I belong?” Passion, heartache, despair, sadness… It all begins in the first volume of this bold boys’ love story.

Source: www.anisearch.com/manga/7391