I wouldn't go into this manga with the same misconceptions as many do when it comes to works such as Killing Stalking as a prime example. At least by my standards, I do not perceive this story as romantic by any sincere means. Yes, the plot is driven by Kwon's desperate want for Himan, but from the way I interpreted it, Kwon (an orphan, the son of a murderer, living in an orphanage that both physically and sexually abused him) upon meeting Himan who just so happened to be kind and attentive towards him as he would towards anybody else (a very, very important fact to note here) Kwon clung to that warmth of being "cared for" not only because his entire life was void of it and he had zero experience of knowing how to react to said positive, warm-feeling emotions, Himan essentially became Kwon's first and ever "want" in life. That is because as emphasized often throughout Kwon's backstory, he was never greedy and never wanted for anything in his life prior to meeting (and wanting) Himan, nor had he ever experienced any means of a single, positive emotion, really.

Hence, he did not know how to act / respond to those feelings in a "normal" way, much in the same way as say a person who has always been void of a parental figure in their life might gravitate towards a teacher or another adult who shows them an unfamiliar amount of care and kindness. For someone who has or has had that means of a solid presence in their life, their reaction and interpretation of an identical interaction would likely vary significantly in response. So in Kwon's case, in meeting Himan (the first ever person not to reject his existence and expressed some genuine fondness towards him) Kwon immediately grew over-attached to such an extent that Kwon dedicated his whole, entire life for just the opportunity to be in Himan's close quarters again: he killed his headmaster so he would attract notice from Himan's mafia father, climbed the ranks from the ground up until he became Himan's father's right-hand man, and since Himan had cut complete ties to his father and family, Kwon went through the extra effort again of taking the sole initiative of breaking the peace treaty between a rivalling mafia by burning down their entire headquarters -- all for the mere CHANCE of them kidnapping Himan as leverage, and hence forcing Himan and Kwon to meet again as strangers.

And you know what? Just about every single SECOND of this story was weaved by Kwon's own hand, unbeknownst to Hiwan and even the reader.

If the story were to include just that flashback alone of Hiwan and Kwon's first meeting, I would go ahead and say yeah, even though a lot of mental instability is at play here as a direct result of some extreme amounts of trauma, particularly in Kwon's case, there is some semblance of "love" here because Kwon really did gravitate towards Himan's affections for him. However, given the fact Himan not only completely fails to remember Kwon (DESPITE keeping his same name from when they first met in their late tweens I do believe), but Kwon's headmaster (his groomer) even tells Kwon as such in the moment; he tells him that Himan is merely being kind and that the way Himan treats him is no different to how he would treat any other one of his friends, which over the course of the story I can definitely see as being true since we see a fair bit of interaction between Himan and his college friends. Himan put his entire life on the line just to keep his best friend safe.

This is where the "romance" aspect cuts off, I think. Because at this point, I think the lines become blurred for Kwon as to whether this chase for Himan is love, revenge, or something sinister in-between. The way Kwon completely cuts Himan from his life following his headmaster's prior claim (harshly at that) only to end up manipulating every aspect of his own life so Himan would just be "fated" to be close to him is sick and its twisted and clearly scales an extreme case of obsession. And while Kwon does have a supposed "soft spot" for him, I think that would be obvious enough considering Himan's existence has been an essential to every single thing Kwon has done with his life up to this point. Yet Kwon doesn't treasure him despite this significant amount of influence Himan is unaware he has over Kwon's life; if anything, his treatment is harsh, condescending, and includes countless explicit threats of SA. It's all very non-con, and often justified as "punishments" whenever Himan does something Kwon doesn't approve of.

And of course, if you read the extra three or so chapters following the 51 conclusion, Kwon rapes Himan as "punishment" and revels in the fact that he's won; his big, life-long scheme worked, and now that he's made Himan fall for him in the process, Himan finally "belongs" to him to treat and fuck as he pleases.

This story, as a romance, is completely fucked. As a narrative on the other hand, it is actually quite spectacular to say the least and that's really hard to deny. There were so many moments that genuinely shocked me so much, there was hardly anything predictable at all about this plot, which made it all the more exciting to engage in. So yes, I regard this story highly, and I would definitely recommend it to anyone to give it a shot!