Chapter 79 — Teaching
Another morning, Ren arrived at Tsumiki's hospital room. He poured her a glass of water, and after she finished drinking, he began explaining the day's lesson.
At present, the lessons were mainly focused on the fundamentals of cursed energy control. As for knowledge related to the Construction Technique, there was little left for him to teach.
After all, what he knew came only from general knowledge he had picked up while interacting with Mai Zen'in, along with some basic information he had studied from books when trying to help improve her technique. But Tsumiki herself was the true wielder of this technique. Through her own research, she would soon grasp insights that outsiders could never access. In that regard, she no longer needed his guidance.
The only exception was the binding vow related to "ten-thousand-fold cursed energy precision" in the Construction Technique. Ren chose not to tell her about it yet.
It wasn't out of selfishness.
His reasoning was simple—if Tsumiki gained that level of precision right away, she might stop pushing herself to improve in that area.
But now, every bit of effort she put in unknowingly would yield ten thousand times the reward in the future.
Ren believed that when she eventually learned the truth, she would be grateful for this decision.
Two hours passed in the blink of an eye.
Teaching Tsumiki was, without a doubt, an enjoyable experience.
Her mind was sharp, and she possessed extraordinary talent in jujutsu.
Ren finally began to understand why Utahime Iori had been so eager to recruit him back then.
Teaching a smart student was truly a pleasure.
No matter what he explained, she grasped it quickly, cutting straight to the core of the problem. From time to time, she would even develop new perspectives from his lessons—ideas that in turn inspired him, the teacher.
She understood everything instantly and could draw connections effortlessly.
The speed at which she learned didn't feel like she was acquiring new knowledge—it was more like she was revisiting something she had already mastered long ago.
"Fushiguro, your sister is really talented," Ren said with a smile as he packed up his bag, turning toward Megumi, who had just entered the room.
Megumi's expression stiffened. His lips twitched slightly, forcing out a strained reaction.
Only then did Ren realize—
this wasn't good news for him.
What Megumi truly wanted was probably for his sister to have no talent for jujutsu at all, so she could leave this world behind and live a peaceful, ordinary life.
Understanding his feelings, Ren stopped himself. He simply patted Megumi on the shoulder and turned to leave.
"By the way, Ren-senpai," Tsumiki's voice called out from the bed.
Ren turned back. She tilted her head slightly and smiled.
"Could I trouble you with something?"
"I'd like to borrow some books on nuclear physics."
As expected, excitement lit up Ren's face again.
This is what a smart student looks like.
No need to be told—they run forward on their own.
Unlike Mai… even when you point her in the right direction, she still can't read the signposts.
"Leave it to me," Ren said, patting his chest confidently.
The next day, he arrived as promised.
Ren didn't just bring her books on nuclear physics—he had also thoughtfully prepared materials on materials science, bionics, and modern manufacturing techniques.
In his view, the two core pillars of the Construction Technique were structure and materials. Just like building architecture, these formed the foundation. So helping her establish a solid base in these areas was essential.
He neatly stacked more than a dozen books by Tsumiki's bedside.
"Senpai…" Tsumiki looked at the pile, clearly surprised. "That many?"
"Yeah," Ren explained. "Besides nuclear physics, I brought some other books related to the Construction Technique."
"From here on, most of your progress will probably rely on self-study."
"…What?"
Ren sat down and smiled as he elaborated.
"There isn't actually that much to teach when it comes to the fundamentals of cursed energy control. And with how fast you learn, I've already covered everything I can."
"Today will probably be the last lesson."
"After this, your growth in cursed energy and technique will depend on your own efforts."
He glanced at the stack of books. "These are just for getting started. If you need anything else, let me know—I'll borrow more from the library for you."
"…I see." A faint trace of disappointment appeared on Tsumiki's face.
Then suddenly, her eyes lit up.
"Senpai… then teach me that."
"I heard from Megumi that you can condense cursed energy into a solid form. Can you teach me that?"
She looked at him expectantly.
"…That?" Ren hesitated.
It wasn't that he didn't want to teach her. But—
At first, he had thought this was part of "basic cursed energy manipulation." However, based on feedback from others like Miwa, the difficulty of this technique was actually extremely high—it belonged to the uppermost level of New Shadow Style control.
If Tsumiki wanted to learn, he could teach her. Just… not yet.
For a beginner, this was aiming far too high.
"Just let me try," she said with a soft smile, blinking lightly. "Didn't you say I'm talented? Maybe I'll be able to learn it."
"…Alright."
So Ren began explaining how to compress cursed energy into a blade-like form.
For him, the process was surprisingly difficult to teach. It was almost instinctual—something he did without thinking. Trying to break that instinct down into clear steps and methods felt awkward and unnatural.
As for Tsumiki…
After more than an hour of explanation and repeated practice, she lived up to expectations—
by showing absolutely no signs of mastering it.
For the first time, a trace of frustration appeared on her intelligent, gentle face.
"Don't worry," Ren reassured her. "This is actually one of the highest-level forms of cursed energy manipulation. It's completely normal that a beginner can't grasp it yet. You can take your time with it later."
"Mm." She nodded.
But then her eyes shifted slightly, and suddenly, an idea struck her.
"Senpai… how about you do it for me?"
"…Huh?" Ren blinked. That was… an option?
"I mean, let me experience it directly." She extended her hand, smiling calmly.
"You should be able to pour your cursed energy into my palm, right? Then shape it there."
"It might not help with learning, but I just want to feel what it's like to create something tangible with cursed energy." Her bright eyes turned pleading as she looked at him. "Please, senpai?"
Ren paused for a moment.
It wasn't impossible.
He reached out and took her hand. Through his fingertips, cursed energy flowed into her palm, gathering, spreading, and enveloping her hand before gradually solidifying into the shape of a glove.
Tsumiki spread her fingers slightly, feeling the sensation of the "cursed energy glove" wrapped around her hand.
"That's amazing!" she exclaimed.
With a crisp sound, several sharp, azure blades extended from the fingertips of the glove.
She gasped again, her bright, clear eyes locking onto Ren's, her face lighting up with joy.
Ren met her gaze and smiled softly—
then quietly looked away.