Honestly...When Hajin mention about how he used to know Hangum,Hangum seems sure his first meeting with Hajin is at the toilet...he didn’t really hesitated when he said that...so, eiter he’s a good liar or he just doesn’t remember Hajin...
And about the parents...there isn’t much that is mention about them...so hopefully we get to know more about them
Yeah, you're right. Hangum really thought their first meeting at the toilet. And I think maybe he lost his memory so his parents homeschooled him. So that why he doesnt remember about the high school stuff and some of his memories starts to come after he met Hajin. And let's hope there's nothing serious about his parents.
... he might know him before the 'toilet' meeting...?
Hmm...interesting speculation you got there
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Why I think Hangum just pretend like he doesn't about him??? Oh, shit. Did his parents knew about their relationship and hate their son to be with a guy??? That why he left him.