Nope, I don't think so. o.o
The other black haired uke is much innocent than he is.
And dude, their both virgins. Not only Rina...
Well, I think he will be a shy seme like in Sabita Yoru Demo Koi Wa Sasayaku.
And he said that RINA is a virgin. So I think he had sex with girls and will take the lead when it comes to Mayu/Yuuki.
Looking at the other mangas from this author. The usual patter tells me that Rina will be the uke bc of the way she is drawn, I'm talking about her eyeees.
That's what I said - he will be the uke, but like in Sabita Yoru Demo Koi Wa Sasayaku he will show the seme what and how to do (well, last part is just my opinion).
"Rina is still a pure virgin, you know". He will be the uke.
Yap yap. ╮(￣▽￣)╭