Responses
The way I interpreted it was that Yasu wanted to know the consequences of his next actions (whether to accept or reject) which is why he asked Rikurou if they'll stay as friends. It had heavy implications of rejection, yes, but it's not a definitive rejection, as you do see him still thinking about it later on. With the last push from Rikurou, he decides to give it a try.
I didn't hate yasu that much, but the story is kind of messy in the middle. yasu wanted them to be only friends, then the next day, he suddenly said he wanted to fall in love with rikurou, why?? I didnt understand but kept reading anyway and the ending was fine.