Aight, so what happened was the blue haired's brother did some experiment with the dad and daughter idk but then his experiment failed and that's why the dad isnt a dad but a kid. Hope my summary made sense lmao.
Also if ur wondering why the kid Shen is looking for his bestfriend (??) is because the kid thought he's in the early years. So like uhhhh
Dad shen is in 2021 -> kid shen is in 2000 smthn. Yeah, so Shen is in his past self and with his past mind.
Also, if this still doesnt make sense, im really sorry hahahahahahha. I just am so terrible at explaining
But not sure if this rlly answers ur question cuz im also confused as hell
the last time I remembered was the daughter and father switching bodies so, what's happening? I dropped this probably months ago because things weren't making any sense