Responses
Shimakawa hated Maya first because he thought that Akira liked Maya so he got close to Maya and then betrayed him. I don't think Akira was ever in love with Maya. I think he fell in love with Maya's dad and that's how he realized he was gay. Akira and Maya have a pretty big age gap so he would have felt more like a big brother.
A couple questions: why did Maya use to hate shimakawa? And did Akira really use to like Maya as a boyfriend?