Naruto Shippuden
Shizune is the niece of Dan Katō (Tsunade's great love who died during the Second Ninja World War). After her uncle's death, she decided to follow Tsunade and become her apprentice. She traveled with her for years while Tsunade wandered the world gambling and drinking until she was finally convinced to become the Fifth Hokage and Shizune ended up being her assistant.
Shizune
