Shin Uchiha was taken aback by Tsunade's words. He had never imagined that this was why she did not want to teach him the forbidden technique called One's Own Life Reincarnation.
After a moment of surprise, however, a gentle smile curved his lips. He stroked Tsunade's lovely face and said jokingly:
"Tsunade, think of it this way. If you ever find yourself in danger, I'll be able to use this technique to save your life."
What Shin Uchiha had not expected was that, upon hearing this, Tsunade tightened her grip on his arm and shook her head emphatically.
"Then I'd rather you didn't save me, Shin. Besides, even if you really did save me that way, I'd put everything in order and then go to the Pure Land to find you."
Shin Uchiha was stunned by her words. Only after standing dumbfounded for a long while did he stroke her hair and reassure her:
"Don't worry, Tsunade. This forbidden technique won't be my only option. I wanted you to teach it to me so I could control those White Zetsu Clones and have them use it. I'm not stupid. Even if I really wanted to resurrect someone, I could simply wait until my Rinnegan's cooldown ended and bring them back then."
Only after hearing Shin's explanation did Tsunade understand. Recalling what he had said earlier, she asked:
"Shin, does that mean you had me develop this forbidden technique for the Six-Tails Jinchuriki?"
Shin Uchiha had no intention of hiding it from Tsunade. He nodded and said:
"I know a little about the Six-Tails Jinchuriki. He's a decent fellow. I want to extract the Six-Tails from his body without harming him."
Now that Tsunade understood Shin's goal, she hesitated briefly before relenting:
"In that case, I'll teach you One's Own Life