This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Paradise Kiss
Towards the end of the manga, it gets clear that Yukari and George's relationship just isn't working - it's very passionate, but they also can't stand one another. They split up, sadly but without any hard feelings, and George goes to Paris in order to finish his education as a designer. Yukari receives a mysterious package with a key inside. The key goes to the room where he keeps all the clothes he made, and he's left them all for her - including the graduation dress. She didn't cry when he left, but she does now.