There was a big, huge misunderstanding. How? I'll explain now
Satoru was a popular basketball player, so it was obvious that everyone liked him, and Suguru's best friend fell under his spell. She fell in love with Satoru, and asked Suguru to ask him all sorts of nonsense, because she knew that Suguru didn't like this Satoru, especially since Suguru wasn't gay so he would like guys. Every day, Suguru would ask Satoru some stupid questions, like 'do you have a pet', 'where do you spend your weekends', 'what's your height/weight'. Apparently, Satoru mistakenly thought that Suguru was in love with him, and Satoru himself was not indifferent to Suguru.
And when Suguru was asking some nonsense like 'what's your favorite color' again, Satoru stopped him and spoke
— "..I think, you like me, right?" — he said suddenly. Damn, that was just a huge misunderstanding.