The art is good, and the story begins with a fun blackmail situation, it's also fun to see how the Yukina uses her experience to write her cell phone novel. But the enojyment stops there.
The development is horrendus, and the love triangle (square, pentagon) is forced beyond believe, and the shoujo tropes are exhausted. The story takes a turn after the 15 first chapters or so, and it's just bland. So so so bland. The characters have no consistency, and their developments are just weird.
I think Mami, Yupinas love rival, and Shigures younger brother, are the only two that actually keep in character and have a thourough and believeable character development over the course of the story.
I guess the reason this manga has such a high score, is mostly due to reviews and scores based on the first few volumes from 2009-2010.