I'm pretty sure the uke is Higashino (megane guy) because Kawanishi had scratches on his back in the last page of chapter 5. That or they switch positions ┑( ̄Д  ̄)┍
I think they switch cause before megane are the seme one. And yes here Kawanashi had scratches... maybe you never see it, I just see the date of the post
Sooo who do you thinks the uke? (≧∀≦)