Responses
I’m thinking that Haesoo is also like Haesol and his only source of hope was her. But instead of being emotionless (like Haesol), he became the overly energetic guy to cover his feelings. Also, their (traumatic) past is the only thing that can make her remember him so, he was happy that his only hope actually remembered him.
Is what I think.
Haesoo also has trauma, he just has ways of coping with it.
I feel bad for Haesol :( Not having a 'normal' family, and idk i feel like Haesoo(haesol's brother) is a bit sus （￣へ￣）