Chapter 9 - 9 (1/2)
The following days, the 3rd hokage didn't use the crystal ball to observe Ryo. However, the latter spent the whole week in the library where he had read all the books related to medical ninjutsu in the Konoha Library and had a certain level of understanding of the medical system of Naruto World.
The medical ninjutsu techniques are based on reparing cells through specific chakra use and also stimulating cell division and regeneration to replace non-reparable cells. This comes together and allows wounds to recover quickly.
Medical ninjutsu uses also shape transformation involving techniques. These techniques can be used also in combat, like that of the ninja scalpel.
The only extreme non conventional uses of these techniques that were shown in the manga were Tsunade's creation rebirth technique, and Chiyo's giving life to Gara technique.
As for the rapid healing of the 1st Hokage, it seems unrelated to medical ninja, but rather a thing related to his own body and cell structure.
However, it is undeniable that his rapid healing was what mainly inspired initial medical ninjutsu techniques. His cells are not something that any ones could have, but the healing technique can simulate it to a certain extent. That's how the mystical palm technique works.
Earlier in the history of the story, the fight between the Senju and the Uchiha was momentarily put to a halt in the valley of the end, where Hashirama seemingly killed Madara. His victory was largely due to his fast recovery.
However, it wasn't a clean victory with no loses. Other than the obvious part concerning Madara's plan, Hashirama didn't survive long after the battle. Ryo suspected that Hashirama's body, no matter how great it was, could not handle the extreme drain caused by the massive amount of regeneration that happened in that battle.
Medical ninjutsu then wasn't flawless and a perfect unbeatable system. And with Hashirama not able to recover indefinitely, one could guess ordinary ninja could only handle so much before breaking down.
When the five Kages fought Madara in the series, this forced Tsunade to use the creation rebirth technique. This pushed her healing rates to incredible levels and made her almost unkillable by regular damage. But this came along with sacrifices, not only did it deplete her chakra levels, it also shortened her lifespan as it resulted in continuous cell division.
The effects of medical ninjutsu are far more immediate than the effects of regular medicine in Ryo's past world. But no matter what techniques used, there were drawbacks. Here the biggest is that healing is paid for with lifespan.
In just one week, Ryo was able to have a clear understanding of medical ninja. Now it's time to start learning it.
The basis for learning medical ninjutsu is chakra control. And with the Yamanaka's secret techniques to control the mind, their own focus is really strong leading to extremely good chakra control. There is a reason that Ino was able to learn medical ninjutsu in the manga.
And within the Yamanaka's, Ryo's outstanding talent along with him using the Yamanaka techniques from childhood should lead to him having exceptional control.
After dinner, Shinse showed her son how to learn medical ninjutsu. She was a strong battle ninja, but she had a great value for Konoha as a great medical ninja.