Mrs. Sasaki is the mother of Yukinari Sasaki and is a minor character.
In the Girls Bravo Manga Series, Mrs. Sasaki makes an appeaance in the first chapter informing her son that Kirie Kojima is using the shower, but warns him a little too late. She makes a short appearance in the next chapter, which also reveals that Yukinari is trying to hide Miharu Sena Kanaka's existence from his mother. In Chapter 3, Yukinari reveals to Kirie that his mother has become aware of Miharu's existence, but thinks she is a ghost. Yukinari's mother made her final appearance in the fifth chapter, where she leaves to tend to Mr. Sasaki, who is sick. Though Yukinari's mother is never seen again, she is mentioned on several occasions and the the 34th chapter Miharu tries to cure Yukinari's allergy to females by wearing his mother's apron, as she believes he may be able to recover from his allergy from a mother's love.
Mrs. Sasaki never makes an appearance in the Girls Bravo Anime Series, but is mentioned on several occasions.