There aren't a lot of works out there that cover mental illness in a way that's both intriguing and respectful. We get to see in detail why Yoseob is the way he is, and how the decisions and actions (or inactions) of others inhibits and changes him. However, he's not completely demonized as many characters who suffer from similar conditions are in other series. The story also touches on the butterfly effect as a major theme as well, which was one of my favorite aspects of the story.
I appreciate that we get to see all of the main 4 characters backstories too. It allows us to connect with them and see why they're making the choices they have and to empathize with them on deeper levels as they have all suffered their own traumas. Overall, they're all pretty fleshed out characters that are easy to become attached to and invested in.
Even if thriller isn't usually your go to, I highly recommend giving this a shot. Just keep in mind there are scenes that include intense child abuse, and somewhat graphic violence against humans and an animal. Each of the chapters that include such scenes are prefaced with a warning, but I like to warn people in advance just in case. I'm somewhat sensitive to gore and was able to get through the series just fine with the warnings.
