It's a fine enough story. There's an inciting incident, a problem that is gradually uncovered and a climax before the story winds down. It has a very structured feel that makes the story good but not great. The characters were also fine, especially the male who was a fairly normal hugh schooler as opposed to an eccentric of other mystery stories like this one.
That being said, the ending was okay, although another chapter on their dating like would have been preferred. I also disliked the female protagonist being a big shot. Its as if the author was not confident in writing her character so added this idol stuff in as a "prize" for the male protagonist. Stories are done better where the female lead is of a similar social standing to the male lead. Lastly the art was uninspiring.
6/10. Fine but nothing more.