Shizuru is Kuwabara's older sister who becomes aware of Yusuke and Kuwabara's association to the Spirit World after watching the assignment tape regarding Yukina's rescue mission. Considerably down to earth and deadpan in most scenes, her role as the tough mother-figure to Kuwabara is what caused him to develop the need to learn how to fight. Her role grows somewhat during the Dark Tournament; in the anime she has a brief romantic connection to Sakyo as he saves her numerous times from demon guards at the stadium, and is given his lighter to remember him by as he dies in the stadium's destruction. This relationship was not present in the manga. Like Kuwabara, she has great spiritual senses, though unlike Kuwabara, she's aware of the biological relation between Hiei and Yukina.Shizuru, standing tall and slim, has long brown hair, brown eyes, and a fair complexion, causing her to share little to no resemblence with her younger brother, Kazuma. Her garments consist of a white, long-sleeved button down shirt; a long, red tie; a light brown, short-sleeved vest; and long, black slacks. She can usually be found with a cigarette in her mouth, and her facial countenance is mostly nonchalant and carefree. Shizuru possesses a mellow and somewhat cynical personality, reflected by her easygoing (and at times bored) facial expression. Shizuru practices a tough love approach when raising Kazuma, causing her to be stern yet loving towards him. In the English anime she refers to him by his first name, while in the Japanese version she addresses him by a nickname Kazu. Though she usually stays out of other characters' affairs, she occasionally takes matters into her own hands, using the same brute force which seems to run in the Kuwabara family. This type of behavior generally seems to get Shizuru in the most trouble, specifically in several instances during the dark tournament. In addition, she has been endowed with sensitive spirit awareness, yet another of her traits which she shares with her younger brother.