Eri Uminaka is a character in the anime film Make a Girl. She is twenty-five years old and is a doctoral student at the university where Shouichi Takamine works as a professor. Eri resides in the same apartment building as Akira Mizutame, a younger associate with whom she shares a close connection.

In her interactions within the university laboratory, Eri often assumes the role of an older sister figure to Akira, offering guidance and support. This protective dynamic is a key aspect of her character, as she keeps a watchful eye on Akira and regularly reports on his condition and activities to Professor Takamine. Her role in the story is therefore tied to this observational and supervisory function, serving as a link between Akira and the professor while maintaining a personal, caring presence in Akira's daily life. No further reliable information is available regarding her personality, deeper motivations, character development arc, or any notable abilities.