I actually feel for Kenta. Probably not confessing would have been worse, because he would have been always questioning on what would have happened if he did or didn't. Sometimes... crushes like that simply come and go after a while (especially if they don't see each other after)... but I suppose it's not the same if that person you are interested in is your friend and you happen to be still seeing them in a daily basis.
Kudos for Daiki for simply rejecting because he already has a gf, even if the situation they both are in is, indeed, weird, as they are still friends and, hopefully, they don't lose that friendship.