Yu Shimamura is one of the minor recurring character in Omamori Himari. She is the class representative of Yuto, Rinko, and Himari's class.
Shimamura is a young high school girl with short violet hair with wide bangs covering some portions of her forehead and sky blue eyes. She wears a light blue, cross-shaped hair barrette on the left side of her hair, and also wears a pair of semi-rimmed glasses with oval lenses. Like Rinko, she also wears the standard Takamiya High girls' school uniform, though her clothes vary outside of school. She also has decent-sized breasts, which somehow does not invoke Rinko's envy over large breasts.
Shimamura has a friendly and outgoing personality, shown when she invites Himari over to the beach. She has also been shown to get along well with Yuto and Rinko (abeit from the fact she has larger breasts than the latter), and often jokes around with them when it comes to romantic topics, especially their close relationship with each other. She is also shown to be an otaku, once doing a witch cosplay at the school festival and referencing a harem dating sim she played while convincing Rinko to make it "a done deal".
Rinko is Shimamura's classmate and best friend. She apparently knows of her feelings for Yuto, and tries to convince her to make some progress with him.
Yuto is Shimamura's classmate. She apparently has feelings for him, but it remains unclear due to her constantly joking around with him.
Shimamura apparently has a love/hate relationship with Taizo. While she respects him as a classmate, she does not tolerate his overall pervertedness. This was shown in one chapter when she, along with Rinko, drowned him for attempting to peep at girls underwater.
- Shimamura's name (which was not revealed until Chapter 49), is derived from voice actress Yu Shimamura who voiced her in the anime.