Just like the subject; it was good, but it went downhill starting from volume 3. I own all the tankoubons.
The heroine, Usami Momoka, I really liked her at first, but when suddenly every guy grows a crush for Momoka and when she suddenly turned into an obsessive lover, it made me dislike her. Even the love rivals, Moa and Hiroki are better than her, and I really like, really like Hiroki more than Usami (I like everyone more than Usami anyway. She ranked the very last in my NamiUsa favorite characters list, with Hiroki being the first, Moa the second, and Satsuki the third). She's seriously a self-centered person who only cried and cried throughout the entire manga, plus being overly-paranoid in her boyfriend (what's the point in a relationship if you can't trust your other half?).
For the hero, Narumi Takahiro, he's okay. He's just okay. And dull. There's nothing special about him, really. But to be the popular and most handsome guy in high school, seeing his past middle school self... it's one of the most cliche thing I've ever seen in this manga (and other mangas). He's a nice guy that actually can put up with Usami's shits.
I was pretty disappointed at the author because she made Satsuki's love unrequited and on top of that, because Amano didn't end up with Satsuki (I ship them somehow). I feel bad for Amano as well, as he loves Usami. This made me annoyed because a self-centered person like her who doesn't even consider Moa and Hiroki's feelings - doesn't deserve being loved by a guy as nice as Amano.
Don't let others' previous reviews fool you, because this is honestly a terrible manga with annoying heroine, dull hero, and more, more cliche storyline as you read through the chapters. The only good thing in this manga is the art.
Read this manga only if you're bored.