Wonderful Days?
Common trope, uncommonly good manga! The second story is really great too, just too short (only one chapter).
Prism Spectrum
For once, the prince-like student council president wasn't an overbearing jerk! OK, he did force Yuu to join the student council but that was the extent of it. This was very sweet with beautiful art. I just wish it had a few more chapters!
Pure Love In Roppongi
Seme came off as a total dick at their first real meeting but it was cute how fast his jerk-facade crumbled when he was unable to get ahold of the uke for a few days. Wish there was more of this. I only gave it 4 stars because it was so short and the ending was rushed. Even just one more chapter of this story could easily have brought it into 5-star range.
Oujisama Ni Narenai
I'd rather give this 3 1/2 stars but this site doesn't recognize half-stars so I reluctantly gave it 4. Here's why: this was pretty good but it very much feels as if the mangaka intended more chapters, it's not quite a cliffhanger (though damn near one) but it also doesn't feel finished in the way an intentional one-shot does. Pity, I really liked where this was going.
Kimi ga Koi ni Midareru