Sanae Tsukimoto is one of Nishikata's and Takagi's classmates and a close friend of Mina and Yukari. Sanae is a very blunt, yet caring and intelligent girl. Known for always having a very stoic expression and demeanor, Sanae likes to keep to herself. She is extremely athletic and is particularly adept at running and swimming. Underneath her typically expressionless exterior, Sanae is shown to care greatly for her two closest friends, Mina and Yukari. The three girls are constantly seen together, both in and out of school. Sanae may have a soft spot for animals. In one instance, Sanae was chasing a cat that had taken Yukari's snack. However, upon realizing that the cat had taken the snack in order to feed its kittens, Sanae decided to let the feline keep the stolen snack.