
okay I'm so confused. I thought the pink haired guy and the main character were friends and then the mc lost his memories of the hyung and couldn't remember who he was and now the mc is with hyung and isn't hanging around the pink haired guy?

There was a really bad transition where suddenly they're all in college now. The Sihoo Myunghan had been seeing was an illusion from his trauma of watching real Sihoo fall from a balcony when they were kids. Hyung (Seungchan) is a childhood friend Myunghan made after Sihoo's mom stopped letting Sihoo come over because she blamed Myunghan's mom for the balcony accident. Time had passed with the 3 of them not talking to each other while Myunghan was imagining Sihoo with him all the time. By the time Myunghan and Hyung meet again it's high school senior year, that's why it seems like they barely know each other again. Flash forward, Hyung confronts Myunghan about his hallucinations and then takes him to meet the real Sihoo, now grown up. It looks like this is going to be the end of the story and in this scene it doesn't really look like Sihoo is at all interested in Myunghan other than to say hi as they used to know one another, but then it looks like the author decided to continue the story into college as, next thing we know, they're randomly all buddy buddy with Seungchan and Sihoo seemingly not liking each other. The implication is that they have a rivalry for Myunghan. Though there was no buildup, we're just thrown into it.

Tbh, I don't think it would have made sense if she hadn't continued. I mean, why did Sihoo look like he wasn't interested in continuing his friendship with Myunghan when Myunghan's mother came to their apartment and begged Sihoo's mother to let them see each other? The second arc explains it. He doesn't really have memories of that time and that, in turn, explains his sudden interest in Myunghan. He wants to know why he didn't contact him when he had moved away.

"why did Sihoo look like he wasn't interested in continuing his friendship with Myunghan when Myunghan's mother came to their apartment and begged Sihoo's mother to let them see each other?"- Because of the order of events and i also think you might be filling in information we don't know in your head. We know Myunghan's mother went and begged, but we don't know that Sihoo knew that or that his mother ever told him. I actually doubt she did as she was trying to cut ties with them. The order of events shows that they never saw each other again until the end of S1, it doesn't seem farfetched at all that Sihoo would have little interest by then, they were just children after all. The played together as children and never saw each other again till senior year of high school. Out of sight out of mind. His pleasant, but uninterested response to seeing Myunghan makes sense.
I also feel like that was a dream, did akki really confess? it just took so long and now finally it happened out of nowhere. I thought it was gonna drag out more.