The summer heat in the ninja world wasn't as suffocating as in Mizuki's previous life. Perhaps the abundant vegetation or the naturally circulating chakra in the environment made the difference. The air felt unusually fresh. As long as one stayed out of direct sunlight, even summer was tolerable—especially for a trained shinobi with enhanced endurance.
Beneath the shade of a broad-leaved tree, Mizuki and Sakura sat on the ground, sharing a quick lunch. Their morning had been spent in live combat drills, and the noon break offered a rare window for discussion between teacher and student.
"Mr. Mizuki, why is your Chakra Scalpel so much stronger than mine?" Sakura asked between bites, a serious look on her face.
She had been training with him for days now—pushed harder than ever before—but was gradually adjusting to the physical intensity. Still, she couldn't help noticing the stark difference in their chakra scalpels. Despite her excellent chakra control—arguably better than most genin—her technique lacked the lethality and sharpness of Mizuki's.
Mizuki nodded, pleased with her attention to detail. "It's good that you're noticing things like that. The difference comes down to more than just control—it's about chakra nature, and how it's applied."
"Chakra nature? You mean the five basic elemental types?" Sakura tilted her head, thinking.
"Yes, but that's only part of it," Mizuki said. "Strictly speaking, chakra can be categorized into seven types: the five elemental affinities—Fire, Wind, Lightning, Earth, and Water—and then Yin and Yang Release."
Sakura blinked. "Yin and Yang? I've heard of the elemental natures, but… those two are new to me."
"It's not surprising. Yin–Yang Release isn't taught much at the Academy level. But you've seen examples, even if you didn't recognize them. Take the Ino–Shika–Chō trio, for example. Their clan jutsu—Mind Transfer, Shadow Possession, and the Expansion Technique—aren't based on the Five Elements. They fall under Yin or Yang."
"That makes sense," Sakura mused. "Yamanaka Ino's technique uses mental energy… so that would be Yin?"
"Exactly. Yin Release governs imagination, mental energy, and genjutsu—while Yang governs physical energy, vitality, and most medical ninjutsu."
Her eyes widened. "Wait… so your Chakra Scalpel—does it use Yang Release?"
Mizuki smiled. "That's right. Most medical techniques are fundamentally Yang-based. And while the basic Chakra Scalpel is a standard medical jutsu, its power can be amplified by a stronger affinity for Yang Release."
Sakura's brow furrowed. "But if it's tied to physical energy… shouldn't mine be just as strong? My chakra control is better than Naruto's and even Sasuke's…"
"You're right about your control. But Yin and Yang aren't just about skill—they relate to your chakra's natural balance. Everyone's chakra leans differently. In my case, I have an abnormal imbalance. My body produces a much stronger Yang component, which amplifies my medical jutsu—though not without side effects."
Sakura caught the shift in his tone. "Is that because of… the Cursed Seal?"
Mizuki gave a faint smile. "You're sharper than you let on. Yes. Orochimaru's Cursed Seal left lasting effects. My chakra is overcharged with Yang energy. It enhances my physical abilities and healing techniques… but at a cost. I'm constantly fighting off breakdown from cellular overregeneration."
"That sounds dangerous."
"It is. That's why I wouldn't recommend pursuing this path. You're still growing. Forcing your chakra into imbalance could cause permanent harm. Control and balance will serve you far better than raw power."
Sakura nodded, slightly disappointed. "I see…"
Noticing her reaction, Mizuki softened his voice. "Don't be discouraged. Your chakra control gives you a foundation most genin can only dream of. And while I can guide you on some things, if you want to master medical ninjutsu, you should eventually seek out someone like Tsunade-sama or Shizune. They're true experts in the field."
"I understand, Mizuki-sensei."
"Good. Now, let's move to the next topic—barrier ninjutsu, genjutsu, and sealing techniques. You'll need them soon. Watch carefully."
Mizuki extended both hands. Chakra surged between his palms, forming a faint shimmering veil.
"This is called a Chakra Shield. It's based on a technique developed by Chiyo of Sunagakure. I use sealing formulas on my forearms to replace her prosthetic mechanism. With fine chakra control, it compresses chakra into a defensive layer."
Sakura leaned forward, fascinated.
"For someone with your Earth and Water affinity, it may even be more efficient. Earth gives stability. Water adds adaptability. My chakra is mostly Fire, so I rely more on control than compatibility."
Sakura's eyes lit up. "That sounds perfect for the Chūnin Exams!"
"Exactly. A defensive technique like this can make a huge difference in combat. But first, you need to master the sealing array I gave you yesterday. Without it, this technique won't stabilize."
"I'll get right on it!"
"Good. That's it for today's combat training. I have other matters to attend to. Keep practicing—but don't push yourself too hard."
Though he knew he couldn't guide her forever, Mizuki hoped he could still offer a little direction, even if only from the shadows.