My first thought when I started reading this was "this is very similar to Seven Days". But then it became really different, as this is more to the comedy side. It's not particularly original, but...it really got to me. I felt sick to my stomach when I realized they'd have to break up when the wedding day came. The way they have their moments and such is is somehow really cute and, to thinking this was a sweet story about how one month made them fall in love, this became something much more intense than that. There are twists to the story there's no way you'll be able to tell and suddenly I caught myself crying along the whole thing.
Even so, neither the uke nor the seme are my type. Tachibana's personality's different from his appearance, as he looks tough but is actually very timid and does everything the uke asks for. Yet, he's strong and has a brave personality. Ryuusuke is the kind of cheerful to the point he's annoying at first, but still manages to get everyone (including the readers) wrapped around his little finger. They are, though, well built and, as Tachibana himself says, Ryuusuke has a lot of façades.
Though I loved it, I can't say it's flawless. The only thing I can particularly say I really didn't like was the sex being this quick and with no conflicts regarding it. So it's okay for an engaged man to have sex with his university friend from whom he's never heard of since and for whom he obviously has feelings for? I don't mind that they're doing something "morally wrong", I mind that they don't care they're doing it. The art's also not to my taste, but it's not bad at all.
Then again, Yukari is A-W-E-S-O-M-E. Finally a manga where woman aren't b*tches! On the contrary, she even helps out and is freaking strong as a character! I love her!!
Oh, and the one-shot was really cute! I like the focus being the lips and wanting each other. Though the author says it wasn't supposed to be sexy, I thought the part where the seme said "you look like you crazily wanted me" was really hot...I guess I was expecting a hot sex scene indeed =X
OBS: If I rated this by criteria, it'd be a 7 or so. But I like it too much so I'm making an exception to real evaluation.