That is a sweet sentiment... on paper. But in the end, the result for Arita is the same, whether Diasuke can't look at him because he is too handsome or repulsive. Arita has a lover who can't stand the sight of him. That, to me, is just sad and cruel.
I couldn't buy it either. Diasuke is written as a socially well adapted college age student. No socially well adapted college age student makes it that far without having been kissed at least once or twice. Maybe it is supposed to be the homosexual aspect that Daisuke is uncomfortable with, but if that is the case, it pissed me off even more because then Diasuke's feelings for Arita are bogus. He doesn't really love Arita, he only sees him as a friend. And his flat refusal to kiss Arita didn't feel like a "cherishing" situation at all. It felt like revulsion. I know I'd start to feel insecure and unwanted if I asked my lover of six months for a simple kiss and was vehemently denied. The very end was poorly written and not thought through. The mangaka just wanted to make a cute excuse for the characters to not have sex and it flopped. Hell, even writing that Arita could get sick by exchanging body fluids would have been better than the half-assed ending we got.
This story was really cute and a bit weird in a good way but... That ending was incredibly stupid. Spoilers
6 months and they won't kiss?! It's not as if they hadn't kissed before! I think it's stupid how in some stories they jump right into sex right after confessing without having any relationship previous to that (I'm fine with it if there's been tension building up or if the relationship started with sex first) but come on. This guy is acting like the typical main character from a harem. I know sex is not everything but at least kiss!!! And hold hands without the costume! At this point it's almost as if Daisuke is in love with Arita in his costume instead of Arita himself. Pisses me off