Here's my take on this series:
Premise: 8/10
The premise of this show is genuinely good, I swear. However, there's this strong soap opera vibe that the director brings in, which kind of takes away from its potential.
Screenplay: 5/10
With such a good premise, it's a shame that the screenplay is quite drawn-out. Many unnecessary scenes are dramatized to the point that this otherwise great show feels like a cheesy soap opera. I'm sure it would be much less 'soap opera' if the writer cut out the unnecessary scenes that don't give impact to the plot. This series could have been wrapped up in just 12 episodes and would have saved a lot of budget.
Acting: 6/10
No, seriously, I'm not a hater. I don't even know most of the main cast. So this is purely from my neutral standpoint. I feel like most of the actors here aren't giving their best performance, especially the one playing Beom-jin. After some digging, turns out Beom-jin's actor is the most popular among the other cast, but he's the one that bothers me the most. There are some villains here, like Gi-hoon, Joon-jae, Beom-jin. But Gi-hoon and Joon-jae managed to portray their villains in their own way. They're natural in their roles without seeming forced. While Beom-jin, I'm not sure if he can't handle his character well or he's just not a good actor. There's something odd about the way he portrays Beom-jin. His acting isn't consistent, sometimes he does it fairly well, but most of the time not. Jaw-jutting and glaring are typical cheap soap opera angry acting we've seen. And that's what he's doing in this show. The way Beom-jin gets angry is really like watching your average soap opera actor. And honestly, his acting seems much more forced compared to other villains in this show. Whether it's his fault or the director's, I don't know.
Scoring: 5/10
Everything feels overly dramatic. Simple scenes that could've been conveyed through dialogue are drowned in excessive dramatic music. And sometimes there's a song in the middle of conversations, no, I'm not kidding, it's literally a background song playing amidst the dialogue between the characters. And it's not a romantic scene with a song playing, it's a regular conversation scene between students. Really weird.
My conclusion: While the storyline premise is intriguing, its execution feels more like a dragged-out soap opera plot. Like i said, this show could've been wrapped up in just 12 episodes, but the excessive drama and flashback scenes make it drag on for 16 episodes. Even after sitting through 16 (each 1 hour long), the mastermind behind the murders didn't face the consequences he deserved, which was quite disappointing. Save your 16 hours for watching another show.