Umu this sucks. I've seen girls like this in real life though. A bipolar girl whose been in a handful of relationships.
This could be better if the MC was the older one and had romance, meanwhile helping her out. But it isn't like that unfortunately.
I don't mind that it's making jokes of mentally unstableness but as long as it's done good. I'm sure there's manga out there very similar but she's a yandere. Making comical situations of these type of people, where we laugh with everyone instead at someone