Hm...there are some parts I love and some parts I really found boring.
First, it kinda reminds me of Junjou Romantica. Guy who's in love with friend, friend announces he's getting married, other guys steps up? Classical Usami-Takahiro-Misaki
Anyways, the good parts are mostly the surprise ones. You see, it's pretty predictable and yet it's not.
I thought Yugi was the seme, to begin with.
The umbrella part was awesome. Not only the whole metaphor, but
! how we realize Yugi's in love with his sempai when we find out the umbrella is his is hauntingly well done.
And then everything I kept thinking proved to be wrong.
! I thought Yugi was already with the sempai, for real. Then I thought Mio's blackmail would work - both times. I thought he'd confess.
I thought Yugi would easily fall for Mio and all the plot would've been for nothing.
I would never expect that four year gap in the story.
And I love the kissing scene, how it's not actually shown, but under what? Yeah, that's right: a NEW umbrella. Amazing!
But then again, I hated the sex scene. I thought it was a horrible, senseless moment for Mio to take a step further and I feel like he totally abused Yugi.
And this is one of the bad parts.
Also, the art is good at times, but some other moments, the characters seem way too childish. I prefer it when they are older, but then Yugi's not as hot as he was before...
And though it surprised me, I didn't like Yugi as a seme. He's so cooler and sexier than Mio (when they are young). Thank God that reversed when they grew up.
Also, it never got me crying, and I cry pretty easily, which I guess can be counted as a bad point for a drama manga.
And last, I thought it was way too short. For a one shot I guess it's as good as the plot could've been, but if it was longer, this would be so much better, because it has so much potential...