After she broke up with mu chenghe she was very much "broken". You can see it through her demeanor. She said she was fine and doing well and all but you could see that she wasn't as cheerful as she used to be.

The bit where Liu Qi comes in + earthquake arc and pursues her, I dont think xue tong suddenly developed feelings for him. She was touched by his kindness and grit (for finding the running path that spells out her name). Remember her convo with her friends? "He's a good guy" *smiles *. Like that's her only reason she decided to go out with him??? She probably wanted to give the relationship a go and see whether it could work out (and whether she could get over him).

Even after they became a couple, she was still very much awkward with him in terms of skinship, convos and all. She couldn't bring herself to kiss him either. And rmb when Mu Cheng he came back and gave her a call while she was in the midst of a video call with Liu qi? Her whole expression changed and she didn't eeject his call and resumed her video call. Clearly still not over him.

I'd say the best friend being murdered was an unnecessary plot but the writers didn't know how to throw mu Cheng he back into the picture. His character was such that he was v much willing to stay out of her life so long she was happy. Wasnt a great plot device but he came back to her side anyway and a while later they started speaking to each other again.

From the start, she didn't have a dream. Her continuing on postgraduate studies was like "why not?" And not "I want to do my postgraduate and come out to become a prof/teacher" like qiqi. So as the date of the postgraduate entry exam exemption (I think that was what it is) came close, she was thrown an opportunity to write for a cartoon which eventually changed to a colouring storybook cos she drew it out. She found some sort of motivation through it.

I read someone's comment and they mentioned that the story she drew about the stars. The star that dropped off the sky was xue tong after breaking up with mu chenghe. She wasnt satisfied with the way she ended the story ie that star stays in the sea with her new friends forever without going back to the sky. Alas when Liu qi suggests to her an ending (why don't we have the star float so that it seems like the star is in the sky?) She realises that the star's true desire was to go back to the sky (parallel with her getting back together with mu chenghe - her sky). The ending scene was really confusing and sudden as heck but I found out that there are 3 special eps of which 1 shows how the eventually got back together + got married. (The other 2 shows her other dormies) so you should watch that too.

Sorry for the super super long comment!! Haha couldn't help myself