Shizune is Tsunade's personal attendant and the niece of her past love, Katou Dan. After Dan died, Tsunade decided to leave Konoha, and Shizune went with her as an apprentice. She has attended to her master throughout all of Tsunade's misfortunes in gambling.
Shizune is a worry wart and shows deep concern and anxiety whenever Tsunade takes out another loan. Yet, she is a loyal assistant who has the best intentions for her master as well as the Leaf Village. Not much else is known about her past, but she is currently continuing her role as attendant to Tsunade back in Konoha. Shizune is also working on missions for the village.
In battle, Shizune, much like Tsunade, is a medical-nin who knows healing techniques, although not as advanced as her master. She also has a contraption on her right wrist, which has five holes that can launch poisonous needles at her opponent. Furthermore, Shizune also possesses the ability to shoot these poisonous needles out of her mouth. She is a quick, fierce ninja who fights for the honor of her master. But first and foremost, Shizune fights to protect the Hidden Leaf Village.