Biwako Sarutobi (猿飛ビワコ, Sarutobi Biwako) was a medical-nin from Konohagakure's Sarutobi clan, and the wife of the Third Hokage, Hiruzen Sarutobi.
In the anime, it was shown that a young Biwako lived in the newly founded Konohagakure, where she attended the Academy. One day, she fell down in front of it and was comforted by Madara Uchiha, whose look frightened her deeply. Hashirama Senju, however, managed to calm her down by giving her a flower he received earlier.
Biwako and her husband Hiruzen Sarutobi met with Kushina Uzumaki and Minato Namikaze shortly before Kushina was to give birth. Because Kushina was a jinchūriki, Hiruzen thought it best for Kushina to give birth at a secure location where Minato could maintain the seal, guarded by Anbu and with Biwako and Taji as her midwives. While they were on their way to the location, Kushina stopped to speak with Mikoto Uchiha who had just had her own baby. Biwako was pleasantly surprised that Mikoto had decided to name the boy after her husband's father but prompted Kushina to leave, warning her as they left that her delivery was top-secret. When Kushina went into labour, Biwako had to calm a hysterical Minato down as he maintained the seal, noting that women were a lot stronger than men. No sooner had Biwako delivered baby Naruto was she struck down by Obito Uchiha who had also killed all the Anbu stationed outside.
Biwako seemed to be as wise and intelligent as her husband, giving somewhat sage-like advice to Kushina about childbirth. She also seems to be very strongly opinionated about women, stating that they were far stronger than men because they can endure childbirth while men cannot. She also wasn't above reprimanding Minato for not focusing on keeping the seal intact during his wife's birth even though he was Hokage.
In the anime, Biwako was shown to believe that when a child is born, the mother should be the first of the two parents to meet the newborn due to what they go through during childbirth, as shown when Minato tried to meet Naruto and she turned him away.
- "Biwako" comes from the loquat, a yellow fruit bearing plant known as biwa (ビワ) in Japan. This fruit was also depicted on the back of her clothing when she was a child.
- While unconfirmed in the manga, the anime showed that Obito's attack killed Biwako during the funeral ceremony for Minato and Kushina.