I had this in my reading list for ages and just finished it today. My feelings for this manga are really mixed though. It's an okay story with unfolding mystery and development. But honestly speaking, I wouldn't recommended it.
The characters are all softies - which I have nothing going against. But this makes convenience for the plot - which in my opinion quite thin and easily resolved. The art style leans towards awkward and clumsiness, a signature of the author. Everything goes in the same direction of supporting this work. So, at the end of the day, it kind of tries to be dramatic but not so dramatic and making things just lukewarm.
Well, on to the romance side - which is not that exciting as I moved further - I did like and root for the childhood friend since the start. Speaking of shoujos and all, the older I get, the more reasonable it seems that feelings and emotions can be mixed up and swayed. I commend here, however, is that the author is very decisive on who the female lead ultimately choose. Both are good candidates. But again, because of my preference, and because of the fact I'm older, I seriously don't see the appeal of a college professor/researcher and a high school any longer. This is sensible romance.
Back to the story, the ending seems damn rush too. If you read this and you feel like "what...?", you're not completely sold, or you feel it concludes but is not that satisfactory - I'm with you.