Seishun Buta Yarou wa Randoseru Girl no Yume wo Minai

In both of these movies, the male protagonist gets forgotten by the world due to their inner difficulties in accepting their current state of the world. They are however remembered only by the female protagonist who tries to save them from "disappearing". 

These both share some focus on the relationships between parents and their children. These sequels in the respective franchises bring further development of the romance between the leads, and have some moments with the female supporting cast. Plots both feature supernatural elements 

These two movies take place after the original TV series and serve as an emotional and conclusive follow-up to a prior plot point. In both movies, the main character has to make a difficult choice between two parallel worlds.