I just thought about this scenario where Person A and Person B are either friends or enemies, well, they have a platonic relationship. One day, Person A has a car accident, or whatever, and stays in coma for some time. During this time, Person A imagines a whole damn romantic relationship with Person B but when Person A wakes up, they realize they imagined the whole thing and Person B isn't really their lover, they have a hard time coming to terms with it.

It could be a happy ending, one sided love, sad ending, the possibilities are endless!!