Set off

After several days of effort from Chen Nuo and Shinobu Kocho, they successfully improved and refined Insect Breathing further, making the transitions between different forms more seamless.

Furthermore, its fundamental power had also been enhanced.

Chen Nuo had even created a new form.

"Insect Breathing, Dance of the Scorpion: Stinger."

Chen Nuo practiced it once more; with a backhand thrust, his arm seemed to suddenly extend a few inches.

This burst of power was exceptionally swift and fierce, the tip of the blade sinking straight into the hard bluestone as smoothly as a knife through tofu.

Shinobu Kocho watched from the side with wide eyes, not wanting to miss a single detail.

"Do you understand now?"

"Sakuragi-sen—"

Shinobu Kocho nodded and then shook her head. Just as she was about to ask for details about the critical points, she was sternly interrupted by Chen Nuo.

"Call me Teacher!"

The situation was different now; the roles of student and teacher had been reversed, and it was Chen Nuo's turn to be the instructor.

Jie jie jie, bring me my pointer!

"...Teacher..."

Although Shinobu Kocho sounded a bit reluctant, she was truly impressed by Chen Nuo in her heart. If he were usually more serious and less flippant, she believed she could definitely call him "Teacher" more sincerely.

After a period of guidance, Shinobu Kocho began to try it herself.

This form of Insect Breathing was extremely explosive, effectively making up for the lack of offensive power in the style. Naturally, she placed great importance on it, unwilling to miss any possibility for self-improvement.

Besides the Breathing Style, research on the Wisteria Toxin had also seen a major breakthrough.

With the help of the demons from Mount Fujikasane, Chen Nuo successfully completed its isolation and purification. Its toxicity increased greatly; a certain Hand Demon would die instantly upon contact.

Since he had gone to Mount Fujikasane with Shinobu Kocho, there was naturally no reason to let that Hand Demon fellow off; it should have died long ago.

This matter was originally the Demon Slayer Corps' own mistake.

As the assessment site for new recruits joining the corps, Mount Fujikasane should have only had low-level demons.

Who would have thought a demon could grow so powerful on Mount Fujikasane, becoming a Mutant Demon and killing many promising newcomers in succession? After learning about this, Ubuyashiki Kagaya felt a wave of regret and self-reproach.

Afterward, he quickly took corresponding remedial measures to prevent such a situation from happening again.

As for the extraction process of the Wisteria Toxin, Chen Nuo was still researching and refining it, striving to achieve semi-automation.

In the current era, the industrial revolution had only just begun. Chen Nuo was like a clever housewife who couldn't cook without rice; he couldn't be expected to push the development of the era all by himself.

It would probably be easier and simpler to just have Chen Nuo go kill Kibutsuji Muzan.

Beyond that, problems like the storage and usage of the Wisteria Toxin would have to wait a bit. One must eat one bite at a time, and things must be resolved one by one.

Chen Nuo himself still had the uv light to further refine; at the very least, it needed to be compressed into a portable version before it could be used in actual combat. Otherwise, it could only be used for defensive purposes.

"Chirp, chirp~"

A familiar bird call sounded from above.

As soon as Chen Nuo looked up, he saw his little Xiao Bai fluttering its wings and landing on his shoulder.

"Snuggle~"

Xiao Bai was here to deliver a message.

Although they had only been apart for a few days, Kanroji Mitsuri always had endless longing she wanted to convey, so Xiao Bai had to work hard as a carrier pigeon, delivering letters back and forth.

"Just in time, I've also prepared some food for Mitsuri. You can take it back to her."

Chen Nuo brought out a large bag of food from the room, weighing perhaps dozens of pounds. Xiao Bai, a parrot, was less than a tenth of its size when standing on it.

"Chirp?"

Xiao Bai tilted its bird head and looked at Chen Nuo, seemingly trying to see from his face if he was serious.

"It does seem like a bit much."

Chen Nuo scratched his face sheepishly; he had overlooked Xiao Bai's transport capacity when he was packing the bundle.

"Chirp!"

Xiao Bai flapped its wings with all its might, but the bundle beneath its claws didn't budge an inch.

"Alright, alright, you just stick to delivering the letter."

Chen Nuo stopped Xiao Bai's attempt, folded the reply, and tucked it into the message tube on its leg. He gave it a few strokes and sent it on its way.

As for the food, it could only be distributed to Kanzaki Aoi and the others at the Butterfly Mansion. He would replenish Mitsuri's supply when he went back later.

At this point in time, Kanzaki Aoi had already joined the Butterfly Mansion. She was in the same batch as Muichiro Tokito for the Final Selection, about a year ago.

But because she lacked the courage to face actual combat missions, she eventually became a nursing staff member with Shinobu Kocho's approval.

"Thank you, Mr. Sakuragi."

Kanzaki Aoi thanked Chen Nuo in a formal and businesslike manner.

But joy could still be felt on her face; after all, the snacks Chen Nuo bought were very much to a young girl's taste.

The three little ones with dot-eyes at the Butterfly Mansion couldn't wait to open the package and enjoy. Kanzaki Aoi tried to be reserved for a moment but couldn't hold it; she was only a half-grown girl after all, just used to acting mature.

The remaining one, Kanao Tsuyuri, looked at the coin in her hand and then joined the group in eating.

"If you eat my desserts, you have to be my wife."

Seeing Kanzaki Aoi so happy, Chen Nuo said sinisterly.

"Ah?!"

Kanzaki Aoi's body jolted. Was it already too late to spit it out?

Although Chen Nuo's looks perfectly matched her aesthetic, she was still young and didn't want to become a mother so early.

The three little ones nearby blinked their dot-eyes.

Is there such a good thing?

They thought, if they married Chen Nuo as his wives, would they have endless snacks to eat in the future?

Kanao Tsuyuri probably didn't understand the sentence and was still enjoying her food unhurriedly.

"Mr. Sakuragi, who exactly do you want to be your wife?"

Shinobu Kocho's fair hand gently pressed on Chen Nuo's shoulder. She looked at him with smiling eyes, and the surrounding air grew mysteriously colder.

"Just a joke."

Chen Nuo laughed, glanced at Shinobu Kocho's hand, and his tone became reproachful.

"Don't you understand the principle of gradual progress? You've trained yourself into an injury."

"It's just some superficial wounds."

"Let me see."

Chen Nuo gently took the back of Shinobu Kocho's hand, turned it over, and checked the injury on the palm and webbing between the thumb and index finger.

Because of years of holding a sword, Shinobu Kocho's palms were naturally not as delicate as those of other girls her age, but they were still slender and refined. However, the large area of abrasion at this moment looked quite distressing.

Shinobu Kocho was still pushing herself too hard. Despite her gentle appearance, she was the one with the deepest obsession among all the Hashira.

To avenge her sister, she wouldn't hesitate even to inject large amounts of Wisteria Toxin into her own body. One should know that the pain caused by such rejection was no less than being sliced by a knife.

However, Shinobu Kocho hadn't reached that point yet. Chen Nuo's appearance had given her new hope and direction.

"If you don't take good care of your hands now, I'm afraid you won't even be able to hold a cup when you're older."

Chen Nuo spoke critically and turned to ask Kanzaki Aoi for external medicine.

Shinobu Kocho's constitution was not like the other Hashira; she couldn't withstand the backlash from excessive overexertion. Once she reached a certain age, various sequelae would follow one after another, just like many professional athletes.

Why did many Hashira retire early? It was because their bodies could no longer support the strain of the Breathing Styles.

Looking at the focused Chen Nuo, Shinobu Kocho for some reason didn't pull her hand back. She just stared at him blankly, her eyes seemingly recalling some past events.

Her sister used to be just as gentle.

By the time she snapped out of her memories, Chen Nuo had already finished bandaging Shinobu Kocho's hands, even tying a bow for good measure.

"...Thank you."

For a moment, Shinobu Kocho didn't know what to say. Looking at the bandages on her hands, her heart gave a sudden thud. She hurriedly dropped those words in a panic and left the area.

"Just a 'thank you' and that's it? I thought I might get a marriage proposal out of it."

Chen Nuo clicked his tongue. Turning his head, he saw Kanzaki Aoi's furious face, her expression like a small beast whose territory had been invaded.

"What's with that expression now?"

"Mr. Sakuragi, you already have a wife. You can't have such thoughts about the master of the house."

"Don't worry, I'm in great health. It's fine if I marry a few more wives."

"That's not the issue at all!"

Kanzaki Aoi's twin tails were almost standing on end. She glared at Chen Nuo huffily, yet didn't know where to start her argument.

It wasn't that she felt Chen Nuo wasn't good enough for Shinobu Kocho, but rather she felt this didn't fit her ideal expectations for love and marriage.

"Alright, alright, don't worry about grown-up business."

Like soothing a child, Chen Nuo reached out and gently patted Kanzaki Aoi's little head.

I have to say, this feels pretty good.

"I'm not a child anymore."

"Ah, right, right, right."

Kanzaki Aoi stomped her feet in anger as she watched Chen Nuo walk away dismissively.

When night came and she saw Chen Nuo again, she continued to stay in the pharmacy with him just as she had for the past few days, working together on the research of the Wisteria Toxin.

The obsession in her heart was enough for Shinobu Kocho to suppress all other distracting thoughts.

"Have you noticed that the wisteria flowers growing on Mount Fujikasane are more vibrant than those at the Butterfly Mansion?"

Chen Nuo took out two wisteria flowers and placed them on the table for comparison.

Although the difference wasn't huge, it was still discernable.

Shinobu Kocho observed carefully and confirmed Chen Nuo's discovery, but a question immediately followed.

"What about it?"

"To enhance the toxicity of wisteria flowers against demons, one doesn't necessarily have to start with the extraction process."

Hearing Chen Nuo's words, Shinobu Kocho understood.

Currently, Chen Nuo had already made a major breakthrough in purification technology. Even if he continued to refine it later, it might be difficult to achieve much more improvement.

In that case, why not start from the source and improve the wisteria flower itself?

Besides researching new cultivation methods, Chen Nuo had other methods like hybridization, cutting, and grafting to experiment with.

It was only because environmental conditions didn't allow it; otherwise, Chen Nuo could have used the Biotechnica he learned in the cyber world to directly edit and trim the genes of the wisteria flowers from the source.

"What do you think the reason for this is?"

Chen Nuo asked again, and this time Shinobu Kocho found the answer herself.

The wisteria at the Butterfly Mansion was cared for by her, yet its growth was still not as good as the naturally growing ones on Mount Fujikasane. The only variable was the presence of demons.

"It seems we'll have to catch some more demons from Mount Fujikasane."

Shinobu Kocho felt a bit of a headache talking about this. To test the purified Wisteria Toxin, she had already killed quite a few demons.

Ubuyashiki Kagaya had also sent people to sweep Mount Fujikasane several times, slaying some of the more threatening demons.

Now the number of demons on Mount Fujikasane was no longer high. If they killed more, it might affect the Final Selection, and then they'd have to trouble other members to catch demons.

Catching demons was far more dangerous than killing them.

It was difficult for non-veteran Demon Slayer Corps members to do, so it was mostly assigned to the various Hashira.

"Why don't we go catch demons outside?"

Chen Nuo suggested, staring straight at Shinobu Kocho, his intentions written all over his face.

"...Alright."

Shinobu Kocho thought about it and agreed. She didn't want to cause trouble for others, and she had rested for quite a long time, so it was time to go out and share the burden with the other Hashira.

As for Chen Nuo's thoughts about her, Shinobu Kocho didn't take them to heart. Before her revenge was complete, she wouldn't consider her own feelings or future at all.

If she could complete her revenge... then she would see.

There was no need to be too conflicted about things that hadn't happened yet... The next day, Ubuyashiki Kagaya learned that Chen Nuo and Shinobu Kocho were going out to catch demons. Looking at the two sitting side by side, he couldn't help but show a motherly smile.

What a well-matched pair; just looking at them was pleasing to the eye.

It was just a pity that Chen Nuo was already married; otherwise, he could have played matchmaker for them.

As the Master, the personal lives of his subordinates also needed to be carefully considered and cared for.

If he knew what was on Ubuyashiki Kagaya's mind, Chen Nuo would definitely have grabbed his arm tightly.

You can still play matchmaker even if I'm married! Don't be so rigid; I can handle it.

"In that case, I happen to have a mission for you. There are rumors of a demon appearing on the snowy mountains to the north. You can go there and take a look."

Ubuyashiki Kagaya said.

"Understood, Master."

Shinobu Kocho replied formally.

"Nuo, your nichirin blade has been forged."

Ubuyashiki Kagaya looked at Chen Nuo again. As soon as he finished speaking, a nearby "Kakushi" member held up a nichirin blade and placed it before his table.

Normally, there was a standard procedure for forging a nichirin blade, but since Chen Nuo's status and situation were different, Ubuyashiki Kagaya made an exception and had a standard-issue nichirin blade forged for him.

Chen Nuo picked it up and unsheathed it halfway. Looking at the water-ripple pattern formed by folding, hammering, and quenching the blade, he nodded in satisfaction.

After all, it was better to have a nichirin blade on hand, just in case he encountered a troublesome demon.

"By the way, the new Water Hashira was also on a mission nearby recently."

Ubuyashiki Kagaya said, as if recalling something.

He hadn't forgotten Chen Nuo's previous request to learn various Breathing Styles, so it was only right to get acquainted with the various Hashira early on.

"The Water Hashira? I heard from Shinobu that he seems to be a man of few words."

Chen Nuo rubbed his chin. While spending time with Shinobu Kocho, the two would occasionally chat about the other Hashira, since they would have to deal with them in the future.

"Giyuu just isn't very good at expressing his emotions, but he's actually a very gentle person. If it's you, you'll get along with him very well."

Ubuyashiki Kagaya suddenly looked forward to the meeting between Chen Nuo and Tomioka Giyuu, and he chuckled secretly.

"Then we won't disturb your rest any further. We'll set out now."

Chen Nuo said, standing up with the nichirin blade. Shinobu Kocho followed, politely bidding farewell, and then they walked out together.