TL;DR Their relationship has been mostly unbalanced till recently. Eunyoung cares for Haejoon because it’s Haejoon and he likes Haejoon. Haejoon cares for Eunyoung largely because Haejoon is a good person at heart, not because he likes Eunyoung (understandably).
But since their Chuseok fight I think Haejoon has grown to be attached to Eunyoung. Now he cares for Eunyoung just because Haejoon is nice, but because it’s Eunyoung.
Ngl, this makes me tear up a bit :"))...
Thats how you know hes a real one
I really like the development of their friendship. Haejoon was kind to Eunyoung at the start (stayed in the dorms with him when he had the chance to transfer, despite the shit Eunyoung pulled on him) — he did this only out of the goodness of his own heart, not at all because he cared about Eunyoung as Eunyoung. If it was any other person, Haejoon would have done the same.
Eunyoung saw that and began to grow attached to Haejoon. Eunyoung cared for Haejoon because it was Haejoon. But Haejoon continued caring for Eunyoung because Haejoon was by nature a good person. Their ways of loving and caring for one another was like this, unbalanced for most of the story **until recently**.
Eunyoung from the early days did things for Haejoon because it was Haejoon and he liked Haejoon. Sure, making food for him was to repay Haejoon for not leaving him alone in the old haunted dorms. But he beat up the bullies, tried to get along with Haejoon, stayed up to make sure Haejoon wouldn’t run out of the house when Haejoon was hallucinating his mother, and tagged along with him even though he had his own friends — in the Stealing arc, Haejoon even brings this up that he doesn’t really like Eunyoung hanging out with him and Juwan, and doesn’t get why Eunyoung hangs out with them.
In the arc where Haejoon goes to his Uncle’s house, Eunyoung mentions in the car that he’s not really interested in going to Juwan’s house on his own without Haejoon. In the arc where Juwan wants to be close to Haejoon but Haejoon seems to avoid him (and it’s revealed he’s awkward and feels bad to Juwan’s mother showing him love), Juwan told Haejoon that Eunyoung won’t hang out with them unless Haejoon is there, which turns out true (which is funny because Eunyoung is awkward with Haejoon after their Chuseok fight).
For most of it, Haejoon cared for Eunyoung because he was just a kind person at heart. But since the Chuseok arc I think Haejoon began to also grow attached to Eunyoung, and he now cares for Eunyoung specifically because it’s Eunyoung. These newest chapters especially show it. He minds his words, doesn’t use violence, and thinks about Eunyoung’s home situation.
A+ relationship. I don’t consider it purely as a friendship, not for romantic reasons (I’m open to this though), but that their relationship is very complex to cover under friendship. Especially on Eunyoung’s side, he’s notably attached to Haejoon more than to any of his friends.