Arisawa Tatsuki is a human, a student at Karakura High School. She studies in the same class as Kurosaki Ichigo, her childhood friend and former karate partner. Tatsuki is a tomboy by nature, brave and sociable. She is Orihime Inoue's best friend and has protected her from unwanted attention since childhood. Tatsuki has practiced karate professionally since an early age and is considered the second strongest girl in Japan in her age group. She possesses spiritual perception and is able to clearly see Pluses, Hollows, Shinigami, and other supernatural phenomena, although she has no unique spiritual powers of her own. Tatsuki is direct and decisive, unafraid to get into conflicts and defend her loved ones. She takes it hard when Ichigo hides the truth from her and insists that he share his problems with her. Tatsuki helps at the dojo as an instructor's assistant. Years later, she continues to live in Karakura and maintains her friendship with the Kurosaki family.
