Wow, that hit both fluffy and hard.
Never thought about it till now, but the whole 'together forever' line we often hear really means something different for these two.
Ok I got one. These two girls are either best friends/lovers and either one or both are graduating. One of them is really upset about it, but the other one seems fine. By the end, they're together (maybe hugging?) and the one who didn't seem sad starts thinking about how sad it is and starts to cry, whoch leads to the crying together. I know it's vague, but it's all I could remember