When Shihōin Naraku arrived at Konoha Hospital, all he saw was Jiraiya lying in a hospital bed, enjoying the care of a young nurse.
Tsunade was nowhere to be seen. Only after asking did he learn that she was in a hastily erected laboratory.
That was hardly unexpected. Creating a pair of arms from Hashirama cells and attaching them to Jiraiya was no easy task.
Tsunade had to familiarize herself with Hashirama cells before she could proceed with her research.
In fact, back when Konoha had selected ninja in the village who volunteered for experiments to obtain Wood Release Ninjutsu, Tsunade's understanding of Hashirama cells had been ahead of everyone else's.
Later, when the sheer number of ninja killed or injured forced the experiments to stop, Tsunade had also abandoned her research into Hashirama cells.
In truth, Tsunade had been reluctant to participate in such things from the very beginning.
As the First Hokage's granddaughter, Tsunade detested research and experiments on Hashirama cells. It felt like putting her grandfather on an operating table.
But for the village's development, Tsunade had been forced to swallow her disgust and participate in researching Wood Release Ninjutsu.
When the experimental casualties grew too severe, Tsunade had joined the others in abandoning the research.
She actually knew the research was continuing in secret, but for the sake of the village's strength, she could not stop it. All she could do was ensure that she took no part in it.
As time passed, those involved in the experiments had naturally come to understand Hashirama cells better than Tsunade did.
That was not difficult to understand.
As Naraku saw it, never mind Orochimaru, Danzo, and the others-even his own understanding of Hashirama cells surpassed Tsunade's.
Her previous indifference had stemmed from her confidence that her Medical Ninjutsu