He is. Its just that the other couple are actually 'old couple' as in they knew each other long before mafuyu and ue. And they just happen to 'date' after mafuyu and ue. I think the reason that the author took their time to develop their relationship is because of that. Like Haruki that knew almost every bit of akihiko, and that other couple who knew each other since childhood. I think the author want to make mafuyu and ue relationship to become like that too. I mean if u really think about it, it hasnt been a long time since they met so i think this is not a slow development. In fact, if the author take big step fot their relationship this story could end early #－.－)
Hello did you know where this manga officially upload?
Why is everyone but the main couple advancing deeper into their relationship???
Does Mafuyu even see Ue in a physically attractive light?