Hanekawa looked at Tsunade holding a knife, momentarily stunned. Could she be planning to use him as a test subject?
Wide-eyed, he stared at her for a few seconds before gritting his teeth and extending his arm.
"Relax, it won't hurt," Tsunade said reassuringly.
As she spoke, she used a fruit knife to make a thin, shallow cut on the back of his hand.
A faint trace of blood trickled out.
It hurt a little, but not much.
After all, she was the most skilled medical ninja.
Hanekawa suddenly remembered a news story from his previous life about a medical student who inflicted more than twenty cuts on himself and only ended up with minor injuries.
"Use your eyes to see, and your heart to feel."
Tsunade raised her hand, and pale green chakra surged from her palm.
A vibrant, life-filled energy spread through the air.
The wound on the back of Hanekawa's hand slowly healed.
"How does it feel?" Tsunade asked.
"The wound is a bit itchy," Hanekawa replied honestly.
"That's because your cells are accelerating their reproduction," Tsunade explained, gently holding his small hand. "It may look no different from before, but you've already consumed a considerable number of cells."
"I see," Hanekawa nodded seriously, absorbing the information.
"But there's a limit to cell division and reproduction," Tsunade said with a suddenly serious tone. "The more you use it, the faster you age."
Hanekawa thought of her Yin Seal.
When the Yin Seal is released, combined with the Strength of a Hundred Technique, any injury can heal rapidly and automatically.
However, overuse could lead to an aged appearance.
In other words, even medical ninjas have limits.
Only by stepping away from being a medical ninja could one transcend these limits—like Senju Hashirama, who was practically inhuman.
He could heal himself without hand signs, without side effects, effortlessly achieving results equivalent to the Strength of a Hundred Technique.
"Do you know the three principles of a medical ninja?" Tsunade asked, shifting the topic.
"Yes," Hanekawa replied, explaining, "They taught us in school."
First, never act impulsively—more precisely, never be on the frontlines.
Second, never give up on treatment unless it's certain the patient is dead.
Third, protect yourself and stay alive at all costs.
Hanekawa felt it was reminiscent of the "survival rules" in battle royale games.
"No matter what happens, you must survive," Tsunade said, patting his head gently.
Hanekawa couldn't shake the feeling that it was similar to the classic line from anime: 'If you come back alive, we'll get married.'
"Let's go to the hospital," Tsunade said, withdrawing her hand.
"What are we going to the hospital for?" Hanekawa asked, momentarily taken aback.
"What, do you want to be a patient?" Tsunade chuckled. "If you're willing to sacrifice yourself, we can just practice at home."
"Let's go to the hospital, then," Hanekawa quickly shook his head. "It hurts too much."
"What do you mean?" Tsunade glared at him. "Did I hurt you just now?"
Now was not the time to focus on that detail!
Hanekawa coughed awkwardly and changed the subject. "Will the hospital patients let me treat them?"
"By yourself? Of course not," Tsunade replied with a smug expression. "But with me there, they'll definitely be more than willing to... receive treatment."
You meant to say "be guinea pigs," didn't you?
Hanekawa followed her to Konoha Hospital.
As she predicted, when the patients heard that Tsunade was involved in the treatment, they were overjoyed to become teaching materials for free.
The day passed quickly.
Hanekawa finally came to appreciate the strength of the C-rank ability "Innate Full Soul."
With his innate Yin Release talent, he could learn genjutsu in just a few minutes.
But learning medical ninjutsu? He hadn't mastered it even after an entire day.
Aside from the greater difficulty of medical ninjutsu, Hanekawa lacked the added boost of a Yang Release talent.
But it didn't matter—there was plenty of time.
As long as he learned three medical ninjutsu techniques, he could synthesize the C-rank ability "Innate Divine Strength."
"Let's call it a day," Tsunade said, glancing at the sunset on the horizon before turning her gaze to Hanekawa, who was sitting on a chair, panting from exhaustion.
The depletion of chakra also meant the depletion of physical energy.
After a full day of training, Hanekawa was naturally worn out.
"Can you still walk?" Tsunade absentmindedly rubbed her fingers together.
A day without gambling made her hands itch.
"I need a moment," Hanekawa waved his hand and said, "Sensei, you can head back first."
"No, you can't rest yet."
Tsunade walked over, scooped him up, and said, "We're going to the casino."
Seriously… not surprising at all.
Hanekawa buried his face in her chest, inhaling her rich fragrance, and continued to rest.
The warm and soft moment passed quickly.
A new day arrived.
Hanekawa woke up early.
After running two laps around the streets, he turned a corner and entered the Konoha Knowledge Bookstore.
"Number 9527, you're amazing!"
Upon seeing him, Tsuchibashi greeted him with the enthusiasm of meeting a long-lost relative.
Hanekawa thought for a moment and understood the reason—Tsunade.
Over the past couple of days, news of him becoming Tsunade's student had spread, and Tsuchibashi was no exception.
Moreover, as a spy planted by the Hidden Cloud Village in Konoha, Tsuchibashi undoubtedly had access to alternative sources of information.
"Uncle Tsuchibashi," Hanekawa asked directly, "Is there a reward for me?"
"Absolutely!" Tsuchihashi couldn't contain his excitement. "Do you know? You're the highest-ranking spy in the history of the Hidden Cloud Village!"
Hanekawa was momentarily stunned. Are the others really that bad?
But on second thought, it wasn't their fault—it was the system's overwhelming strength.
Other spies couldn't possibly evade detection by Konoha's various sensory and intelligence ninjutsu.
The Yamanaka clan's memory extraction alone could end any hopes of advancement, let alone infiltrating Konoha's upper echelons.
Of course, there was another reason—geniuses wouldn't be sent to be spies.
Oh, except for Shimura Danzo.
"I sent a message to the Hidden Cloud Village yesterday. We should hear back in a couple of days. Come back then," Tsuchibashi said after calming himself. "Keep up the good work; the future is yours."
Hanekawa was his subordinate—his success meant rewards for Tsuchibashi from the Hidden Cloud Village as well.
"Understood," Hanekawa said with a determined expression. "For the Hidden Cloud Village!"
"For the Hidden Cloud Village!" Tsuchibashi echoed.
"By the way... about the royalties for Demon Slayer Ninja, could we settle them?" Hanekawa coughed lightly, changing the topic.
"Of course."
Tsuchibashi smiled, pulling out a bankbook. "Here are the royalties from the publication up to now."
Hanekawa opened the bankbook with anticipation.
Twelve million ryo!
I'm rich!
He hadn't expected the royalties to amount to a third of the bounty on Sarutobi Asuma's head.
"I'm planning to release the middle volume of Demon Slayer Ninja this week. You can look forward to next month's royalties," Tsuchibashi said, patting him on the shoulder. "Does your… friend have any other ideas?"
"I'll check with them," Hanekawa replied, putting away the bankbook. "I don't know yet myself."
It was true—he hadn't decided what to write next.