
I just started reading this, and it was funny to find the little detail about the MC sending numbers 4 to his murder to hire account. The number 4 is considered an unlucky number in some Asian countries because it's pronounced the same as "death." So it makes it even funnier that he's cursing the ML like this when sending money to that account.

Despite many complaints about the rope scene, it does make sense. Remember that the ML is obsessed with the MC, he has all his merchandise, and even went to the same school to be close to him. To think that the kiss upset and ruined his relationship with the MC and that they'd never see or speak to each other again—an introverted (possibly depressed too though it rarely addressed in mangas) teenager with a terrible reputation and barely any friends—I don't see it as so far-fetched that he thought of suicide.
If they made a real life version of this manhwa, I think Seo Kang Joon would be a good choice for the role of Jeongmu, both are very handsome with light brown eyes