After completing their bandit extermination mission, Kōki and the others returned to the village.
Once they were back, Mamoru Uehara needed to report the mission's details to Hiruzen Sarutobi. Katsuto and Yui had suffered some injuries in battle. Though the wounds were minor, they had also expended quite a bit of energy and said they wanted to go home and rest. Kōki had things of his own to do as well, so the group disbanded on the spot and went their separate ways.
As Kōki walked along the road, he felt a little disappointed. His low spirits came from the feeling that this sort of C-rank mission did nothing to improve his strength. Or perhaps his expectations had been too high. He recalled how, in the original story, the Child of Prophecy, Naruto Uzumaki, had faced Zabuza Momochi, a famous missing-nin from Kirigakure, on his very first C-rank mission.
His own first mission, however, had been nothing more than a simple bandit extermination. There had been a small complication, but it had been easily resolved, leaving him feeling quite a gap between expectation and reality.
Kōki took several deep breaths, patted his cheeks, and readjusted his mood. He warned himself, Don't rush. Impatience is a great enemy on the path to becoming strong.
Before long, once he had calmed down, Kōki headed toward Konoha Hospital.
Ever since Kōki had transmigrated into the Naruto world, he had frequently visited Konoha Hospital. At first, he had only gone for follow-up examinations to see whether his body had fully recovered. Later, he often injured himself while training and had to make trips to the hospital as well.
Over time, Kōki had begun wondering whether he could learn Medical Ninjutsu. That way, he could treat himself whenever he got hurt without delaying his training.
But after trying to learn Medical Ninjutsu, Kōki unexpectedly discovered that he had an outstanding talent for it. He could basically begin using a medical jutsu as soon as he learned it, and after using it a few more times, he could master it, even performing it better than some highly skilled medical-nin.
Even the medical-nin teaching him could not help marveling that Kōki was a born medical-nin, fully capable of becoming as great a medical-nin as Princess Tsunade. Later, they even felt compelled to suggest to Hiruzen Sarutobi that Kōki focus exclusively on studying Medical Ninjutsu.
The suggestion had startled Hiruzen Sarutobi at the time, and he had nearly forbidden Kōki from continuing to learn Medical Ninjutsu. To Hiruzen, Kōki's talent for Medical Ninjutsu was nowhere near as important as his Wood Release.
Only after Kōki repeatedly promised that he would not give up Wood Release, and that he was studying Medical Ninjutsu solely to train more effectively, did Hiruzen abandon the idea of forbidding him from learning it.
Of course, Kōki had another purpose in studying Medical Ninjutsu. Learning medical techniques was not entirely for the sake of training more effectively. He also hoped to uncover his body's secrets through Medical Ninjutsu. He knew that his Wood Release was the product of human experimentation-being fused with Hashirama Cells. He understood perfectly well that, strictly speaking, that experiment had not succeeded. It would have been more accurate to call it a failure.
The original Kōki Itō had died during the experiment. He had only successfully come back to life because Kōki had transmigrated and taken everything over.
Strangely, the body he occupied had shown none of the incompatibility between soul and body that Orochimaru experienced after using his reincarnation jutsu. In his case, it was as though this body had always been his, fitting his soul perfectly without the slightest discomfort.
When he had first transmigrated, he had been rather lost and had not known what had happened to his body. Only the memories in his head and his healthy body told him that the human experiment had succeeded, that he had survived, and that he now possessed Wood Release more powerful than Yamato's, along with a sage body.
But all those unknowns still left a shadow in Kōki's heart. He only knew that he had somehow succeeded, without understanding how. He did not know whether the successful human experiment had left any aftereffects or hidden dangers. After all, anything involving human cells was profoundly complex.
Although he felt no discomfort when using Wood Release, and his body seemed to have perfectly inherited Hashirama Senju's sage body and its powerful vitality, he still treated his body with caution.
His life was at stake. Having transmigrated once already meant that the goddess of luck had smiled upon him. If he died in an accident caused by some hidden problem in his body, who knew whether he would get a second chance to transmigrate? So until he fully understood it, Kōki restrained his use of Wood Release.
This strengthened Kōki's determination to learn Medical Ninjutsu. Later, he frequently asked Hiruzen Sarutobi to help him obtain books on Medical Ninjutsu, deepening his understanding of human anatomy and laying the groundwork for studying his own body in the future.
At the same time, to compare his internal anatomy with that of other shinobi, Kōki went to Konoha Hospital hoping to treat different shinobi with Medical Ninjutsu. He wanted to familiarize himself with the anatomy of different people, then compare it with his own body and gradually discover the key to his body's successful inheritance of Wood Release.
But unexpectedly, because he was too young and was not even an official shinobi, none of the hospital's patients were willing to let Kōki treat them.
Although Kōki was confident in the medical techniques he had mastered, there was nothing he could do if no one would let him treat them. This led to the peculiar situation in which, after mastering Medical Ninjutsu, he possessed extensive theoretical knowledge and superb medical skills, but not a scrap of actual treatment experience.
His reason for going to the hospital today was simple: he was going to get his medical-nin certification. He had previously learned that treating illnesses and saving lives with Medical Ninjutsu required a special examination. Only after passing it and receiving certification would he count as a true medical-nin.
Such a complicated process made Kōki realize that becoming a true medical-nin was no simple matter. Shinobi on the battlefield who had merely learned some Medical Ninjutsu could not really be considered medical-nin. What they had learned were medical measures for administering first aid after being injured in combat.
In addition to mastering such first-aid measures, true medical-nin needed to master a much broader range of things, such as ensuring that treatment left no lasting ill effects on the body, or, at an even deeper level, treating a shinobi's mind. It was precisely these requirements that made training a qualified medical-nin extremely difficult and required such a substantial investment.
This was also why, during the Second Shinobi World War, Tsunade's proposal to assign a dedicated medical-nin to every shinobi squad had met with unanimous opposition from the Konoha High Command.
The Konoha High Command knew that anyone capable of becoming a medical-nin had to be a shinobi with at least some degree of talent. Moreover, the war had been raging fiercely at the time, and their priority had been the number of combatants on the battlefield rather than the number of medical personnel treating the wounded.
They could not have those who were fighting go and study Medical Ninjutsu to save people. Besides, Medical Ninjutsu was not something that could be learned all at once.
For Kōki, however, this medical-nin examination posed no difficulty whatsoever. The hospital's medical-nin had even said that they could simply consider him to have passed. But there was one crucial issue that Kōki could not avoid: to take the examination, he first had to become a Genin.
This was also one of the reasons Kōki was eager to graduate.