They do their best to stay in touch but it's too much, they always knew it would be. lwj in particular has mountains of academic catch-up to do - official exams to make up, to prepare for, application exams, and that's without considering his grief, the sudden isolation, or culture shock.

It's not so much that they break up as it is that they are already broken, albeit not voluntarily. wwx's own senior year becomes complicated and he loses consistent internet access after he's kicked out of the Jiang home, and it only gets messier as he steps up to help wq and wn.