I Hear the Aria 1995 on netflix

Takeshi Harada is a single office worker bad at socializing. His colleagues create rumors that he is gay and interested in male employees but Takeshi is sure he is not. One day while eating his lunch at the rooftop a man called Makoto Nagasawa approaches him and tells him he was transferred from a Hokkaido branch office to work here. While facing each other Takeshi feels strange in his chest. He wonders if he is interested in men and comes to terms with his feelings for Makoto. He decides he wants to confess to Makoto.