To be honest I think one-sided setokano is pretty interesting
At first the voices are small: I cannot believe what you have become but they grow into something bigger over time. They whisper to Kano as Seto's hand brushes against his when they walk to school together you're disgusting. He does his best to shut them up, to quit paying attention to the voices and the thoughts that plague him now so often.
When they change clothes in the room they share, Kano turns his back to Seto that's better now, isn't it? Kano covers his ears at night so he doesn't have to listen to Seto's light muttering, his heavy, even breathing. Slowly the dreams come to him, of Seto smiling under his lips as they hold each other close. When Kano wakes up the voices start back he would think you're disgusting.
Boys don't have crushes on other boys they hiss and boys especially don't get crushes on their brothers.
Kano pushes his thoughts down. He tries not to focus on Seto's mouth when he talks. He tries not to notice the way Seto's eyes crinkle as he laughs. He tries not to think about anything but what he needs to do: stop.