???

idk i don't think this is an au... chinese manhuas love the highschool break up trope then they meet as adults tbh

I think is au as well. The chapters are named like it might be a dream or something. I will riot if they broke up in hs after such a short relationship.

I don't think so, I think it's him coming to terms that his highschool romance was "dreamy" and he's turned his life into a nightmare by breaking up with Ren Zhichu.

This is def a time skip. Them leaving off at the decision of college admission. The messages that he sent that did not get delivered. Clearly suggests that they broke up in high school for some reason (reason will probably be revealed gradually probably some sorta misunderstanding or I had to let you go for your own good thing) and now they are both working together and they will after lots of misunderstanding start dating again most probably. As the comments said this is a v common trope in Chinese BL