Basically: read it for its shoujo. On all levels, it is a shoujo, which is why, for so many of their foolish mistakes and plot cliches, it's a great shoujo manga. But on an writing artisan level: awful, absolutely awful.

Why you shouldn't read it:
The only reason I gave this such a horrible rating was because it left an awful, awful taste in my mouth. Granted, most romance mangas boast the freedom of churning out cliche after cliche, so I'll give this that, but I was actually surprised that there was no amnesia arc.
Bottom line: do not read for plot. Read for the cliche drama.

Why you should read it:
Some realistic situations between a developing and maturing young couple. There were times where I had to go "Damn, that's a pretty relevant issue! You go girl, think it over!" The normal insecurities were touched upon as well. I'll have to admit that because of their character, their lack of communication (which nearly made me pull out my hair at some points) was a great consistent issue to pick away at due to each of their flaws and expectations/perceptions.
Bonus! The writer actually also covers their development into adulthood! At least, the major developmental milestones as individuals and how they react to each other's changes!
Bottom line: read for character development BECAUSE of their relationship.