Who is Sensei's Wife, Shizu (Ojosan) from Kokoro and what is their importance?

Sensei's wife, Ojosan, is described as a beautiful, young woman. Strong willed and ourspoken, Ojosan is a dutiful wife, who loves her husband. She does, however, have no problem asserting her opinion in regard to her husband's behavior. Soseki and K both fall in live with Ojosan over the course of the novel.