After hearing this, Butterfly Shinobu was silent for a while, and then slowly replied after a long time.

"Of course, the principle of the transaction is to barter to achieve fairness and justice that is mutually acceptable. But I don't seem to have any items that I can trade with Yahara-kun, right? ”

This is true, in terms of the unfathomable strength displayed by Yahara, everything that Butterfly Shinobi has seems to be insignificant, not to mention that he has already owed a life before, and the situation is already a little weaker.

"No, Miss Butterfly is proficient in pharmacology, have you forgotten?" Yahara smiled at the former, looking at the butterfly's eyes full of puzzlement.

"I want you to help me complete an experiment that is enough to change the situation between the Demon Slayer and the demons, and if it succeeds, the effect achieved is incomparable to the opening of the markings."

Butterfly Ren was slightly stunned, and then her pretty face changed slightly, and she said in surprise: "What is that?" ”

As the weakest wrist strength among the nine pillars, she focuses on using speed and toxins to make up for her shortcomings, but even so, she is still not as brave as Tomioka in the face of the upper string, like a fluttering butterfly that can't do harm.

But this miraculous man in front of him brought incredible news again and again, just like a god sent by the heavens to end this blood feud.

"Research out the medicine that turns ghosts into people" Looking at Butterfly Shinobi's delicate pink cheeks, Yahara blurted out: "After all, my methods are not perfect, there must be a backup plan." ”

When Butterfly squirmed her thin lips and whispered yes, the seemingly equal deal was successfully concluded, and the system in Yahara's mind sounded.

["Otherworld Travel System" Reminder: The unlocking conditions of Secret Letter No. 2241 have been reached, please check]

The sudden sound startled Yahara, and he almost couldn't help but stand up.

Butterfly Shinobu was also stunned, looking curiously at the unnatural look of Yahara, thinking that he was too excited, pursed his lips and smiled.

After the discussion, Yehara looked at the dinner that was still warm on the table, ignored the secret letter that was inexplicably unlocked, and continued to start the dry meal journey.

Greeting Butterfly Shinobu and saying that he would give her the exact news tomorrow morning, Yahara returned to the soft big bed comfortably.

Idle to open the distorted magic eye to scan the surroundings to observe the situation, Tanjiro's three boring narration, butterfly ninja... Ahem, don't look at it, Yae and Lingyuzi and Chestnut Blossom Chanel and others seem to be planning something.

Make sure that no one is close to the room, and then Yehara can open the system page with confidence and check the secret letter 2241 that has just been unlocked.

[Secret Letter No. 2241: The basic principle of the transaction is fairness, do not lose big because of small things, and remember to weigh the benefits!! 】

After the scan, Yahara fell into thought.

It stands to reason that during his previous trips, he had not only traded the gadgets he brought from the real world in exchange for money, but this secret letter did not appear, could it be that there was a precondition for unlocking the first secret letter?

In a flash of inspiration, he suddenly remembered the hint of the first time the secret letter appeared:

A change in the host's mood was detected.

Could it be that this "other-world travel system" is actually an idealistic system, and then it goes to various worlds to retrieve the host's mood ups and downs to unlock the secret letter?

With a mood of nonsense and complaining, Yahara didn't even bother to ask the system after reading it, and turned off the interface and fell on the bed.

The breath gradually calmed down, and the thoughts were allowed to spread out in the mind, like floating clouds floating in the sky.

Next, there should be four left in the upper and lower chords, and it cannot be ruled out that Onimai Tsuji has already cleaned up the staff in anger, but if he has a little brain, he won't do it.

I really look forward to the scene where I can get the ghost king's physique, and the most worthwhile thing in this world besides the breathing method is it.

After leaving this world, the ability to distort the Demon Eye will disappear like a sophist, and the only thing that can really be left is the Ghost King's physique transformed by using Wuwei Transformation.

Although the strength that can really be exerted depends on the adaptation of physique and ghost blood, the ability of immortality is still the most suitable for him.

Who would refuse a self who can't be killed?

The next morning, sweeping away the depression accumulated in his heart, Yahara looked at the sunlight rushing into the room, and felt refreshed, and couldn't help but open the door and go out for a walk.

Walking into the training ground at the back of the courtyard of the butterfly house, under the cover of a dense tree, two energetic newcomers to the ghost killing team were holding stones to exercise their physique, and the atmosphere was quite hot.

"Ah, it's Yahara-kun!" Wiping the sweat from his forehead, Tanjiro turned his head to see the figure of Yahara holding his hands on his chest and silently admiring it.

Small kiosk

"Tanjiro, aren't your ribs broken, and you're training so soon?" Under the distorted eyes of the X-ray effect, Yahara could clearly see the injuries presented by the other party, and said with a frown.

Hearing him say this, Tanjiro put down the stone, his expression resolute, and his voice was sonorous: "Of course, in order to become stronger, strong enough to defeat all the evil spirits he encounters!" ”

"They also have a tragic past, they are poor creatures, and I can smell that."

"Then it's up to you," Yahara said helplessly, shrugged. The problem of being naturally warm-hearted and loving to manage things just can't be changed.

looked around, but didn't find the familiar yellow figure, and asked curiously, "What about the one who called my wife Shanyi?" I remember he was brought back by the Ghost Slayer Follow-up. ”

"Shanyi he..."Tanjiro was depressed, and his face was unbearable: "He was poisoned by the lungs, and he coughed violently when he exercised, and he is still recuperating." ”

Hearing this, Yahara muttered for a long time, said goodbye to Tanjiro, and turned around and walked to Butterfly Shinobi's research room.

I didn't expect Tong Mo's poison to be so powerful, even Yahara didn't dare to use Wuwei to change my wife Shanyi casually.

One is that there is no worthy reason and value, and the overflow of the heart of the Virgin cannot do it;

As a traveler facing many worlds, it's a smart choice to do the right thing.

The second is that he can't use the breathing method, his body is no different from ordinary people, and if he can't bear the transformation and makes a monster, the consequences will be unimaginable.

If a spell spirit is born in the world of Demon Slayer, I am afraid it will be another catastrophe.

The faint sunlight poured down from the glass, shining on the slender and petite body of the butterfly ninja, which was extremely moving.

Gently tapping the glass to bring the butterfly shinobi immersed in the herb reaction back to reality, Yahara directly recounted the location and requirements of the experiment.

I thought she would be resistant to the identity of the pearl ghost, but Butterfly Shinobu always kept smiling and did not feel uncomfortable at all.

"By the way, do you have any records about the changes of Mr. Masaku, Miss Butterfly?"

After saying that, it suddenly occurred to him that he had almost forgotten about it because he had been dealing with other things.

After thinking for a moment, Butterfly Shinobu took out a stack of papers from the box under the laboratory table and handed it to Yahara with both hands: "This is a record of my observations of Mr. Masaku every time I am in the Butterfly House, so it should be able to help, right?" ”

Touching the thick pile of paper in his hand, feeling its weight, Yehara's eyes burst into a fine light: "Of course it's useful!" ”