I usually don't post about, let alone review, shows that are already highly represented (I don't post a lot as is), but this show truly deserves the 5 hours of time anyone who can handle violent content (EXTREME bullying and extreme injuries!).
That said, I honestly recommend you NOT read any reviews before watching. It's so satisfying to go in without others' perspectives. A clean slate is perfect for this IMO. With that said, this isn't really so much full of spoilers (as I don't really go into plot much) as it is a summary of the characters which may still be more than some wish to read about.

We start with a stone-faced high school kid, a complete loner whose parents, divorced middle class workers (an academy math teacher and athletic coach), pay him little attention. He dives into his studies like his life is on the line, goes to cram academies and not much else. When he places first in a math competition (that is either schoolwide or regional/national-something bigger than their class), the guy who places third (a rich, entitled kid who rebels by drinking, smoking, and buying fentanyl from a hulk-like runaway/homeless/orphan thug in a gang that exploits teens) gets irritated and makes him a target.

From there, violence becomes the main feature, but the reasons for being violent, the methods of fighting, and the approach to it are different for all of the key figures. There are, of course, lackeys that gang up on people in swarms, but they picked a truly unique lead here. How he fights is pure strategy. He's truly weak-his stamina makes him take 50% longer than classmates to run a distance most take 6-7 minutes to do, so he instead uses his brain. He scans his environment, calculates the best strategies he can, and goes for quick shocking moves, not a steady flow of hard punches. He is, to be frank, a badass in terms of his brain. His lack of social skills, though, is less enviable, but his apparent lack of need for friends/him seeming fine flying solo does make others (like the attention-seeking third place kid who we can assume has some home life issues/parents pressuring him to be the best because "how can you lose to someone without our abundance of wealth?" but we don't actually see the background of them because it would distract from the short and fast-paced show's focus).

Alongside him are two other classmates, one right away, another soon after. From the beginning, our second lead is a righteous classmate whose MMA skills are unparalleled, a sweet guy who works multiple jobs to help take care of the grandmother he lives with. He protects not just the lead from others but others from the lead early on. He gets along with everyone, is truly good-hearted and generous, and is impossible to dislike for anyone but the few bullies with their ego issues who can't stand someone being so well-loved by everyone, someone so assured in who he is that he doesn't mind anyone's opinion of him or anger easily at all. They become friends in a quite unique set of encounters day to day, but it is a hard-earned friendship for the golden retriever-like faithful pal.

Soon after the initial two have been introduced to us, a transfer student enters the picture. He is a rich kid who was bullied severely at his former school. His family situation, though, is nothing to envy. His father is an Assemblyman who we learn adopted him solely to improve his image. There is nothing but annoyance and hostility because he is a nuisance-he isn't winning awards that the Assemblyman can show off but instead is occasionally taking him from work when beaten up by other schoolkids at the school of all-wealthy people.

This show's fight scenes are incredibly powerful... for something with only 5 hours of viewing content, I found myself truly impressed by the sheer variety of reasons for fighting and ways people end up fighting people who are often total strangers. It wasn't a variety pack that was just "create all kinds of scenarios and throw them all out there to just have as much violence as possible" from my viewing. Nothing seemed farfetched, a scary fact. Sure, the chance of ONE PERSON having this assortment is farfetched for reality, but this almost has a "Girl From Nowhere" "tour of this town's adolescent violence" feel through the lens of the ML.

I always LOVE when students look like everyday students. Seeing a load of flower boys/princess-like girls is harder to get immersed in. I love that this particular ML, despite being able to "glow up" and look very pretty (I've seen him in such roles), looks like a pretty common, average kid. He isn't this tall model-looking guy with an anime-like face but a kid whose expressions make him seem generally not-so-attractive. The golden retriever who can fight like nobody's business, well, okay-he's like a young Jang Ki Yong and no one's going to deny he's got some really handsome moments here. The third player, too, can look rather intriguing in a way that has a bit of what make Lee Soo Hyuk and Noh Min Woo so drop dead gorgeous. He is an awkward squirrely skinny kid here, and his hair is intentionally made unflattering, his glasses not really doing much for him, either-they made the two friendless ones LOOK like kids who don't have friends. Pretty impressive on makeup/hair/wardrobe and of course the acting, too!

One thing really stood out about these kids' faces, the ML's in particular. Watching the stoic lead show warmth as time goes on and seeing the transformation in his EYES when slowly getting a bit closer to the SML is powerful! The acting is truly spot on start to finish, and there's a scene where the SML (golden retriever) mentions feeling a bit strange as he expresses how the lead, this kid who was nonchalant and "are we close? Do you know me?" with people who talked to him when attention went his way, is actually a really warm, considerate, kind person... it was one I'll remember a long time. Despite there being SO much violence, we really do see these awkward kids blossom... and one fall and develop intense envy and bitterness and sadness/loneliness and derail for that matter. The ML's development, though, is kind of magical. Even the end is showing a still-transforming adolescent. He's one of the most intricately written teen characters I've seen in a LONG time (maybe ever), and his delivery was IMPECCABLE.

You will feel such a wide range of emotions... sometimes the violence will be deeply satisfying (even though it shouldn't), other times deeply disturbing and even heartbreaking! It's like these actors really did punch out all of their characters' strongest emotions with every single punch, throw, etc. For the male lead in particular, we see the journey of his psyche and can tell his emotional state from the way he engages in violent acts. It's truly well-done. I'm REALLY stoked it's getting another season, something I rarely feel so excited about!