At its best, the art is mediocre and often its worse than that. There's no sense of originality or depth. The author only has two tools in their arsenal: cliches and disjointed plot twists. Cliches can be nice, but only when they're used in tangent with originality. And plot twists can be great, but only when you can look back at the story and see how the plot twist was coming all along. The closest thing to an actual interesting plot device was in chapter 10, when Yuri read Lizzie's notes, but his reaction was bland and shallow so it ruined any potential for good plot or characterization. Yuri is a pissant of a character, without any real sense of identity. It feels as though he's supposed to come across as a mundane yet chivalrous character, but in light of the literally life-threatening circumstances he's supposedly engaged in, his empathy for others is entirely unrealistic and only further cements him as a walking ball of manga cliches, doing nothing to give him an actual believable personality.
The setting of the story is nothing but a backdrop for a shallow accidental harem romance story. It's as though the author realized that there needed to be some kind of hook to set this story apart from all the other harem comics, but just threw something together. In fact, throughout the entire manga, it was never explained who commissioned Yuri's assassination or why. No, we're just supposed to accept that an unimportant high school student had assassins out to kill him and move on. But this manga isn't nearly compelling enough for me to be willing to suspend my disbelief.