He Guanguan, who didn't care about anything, was originally the most serious about grades, but he gradually changed himself after meeting Xie Juntian and Zhuo Yangyan.
"Guan Guan... If you want... You can be my Xie Juntian's sister... We won't mind your past."
But... He Guanguan seems to be unable to accept his past self
Intention: Under this sunset, we are still the youth we once were, the iron triangle we once were