[The meeting with Aoi Kanzaki was just a small episode. Even though objectively Aoi Kanzaki is also a beauty, you don't pay much attention to her.]
[A few days later, the demons promised by the Demon Slayer Corps are here, and the demons are being escorted by Kochō Kanae and Kochō Shinobu.]
[ Kochō Shinobu told you that this is a demon that has killed many people. Don't feel guilty experimenting on it, this demon has committed many atrocities.]
[Kochō Kanae smiles wryly while listening, but she knows that this is also Kochō Shinobu's way of comforting you, so you won't experience any psychological pressure, after all, you're just a child.]
[ You nodded at Kochō Shinobu, then looked at Kochō Kanae, and said seriously.]
[ A world where humans and demons coexist peacefully is impossible, but if demons turn back into humans, it becomes possible.]
[ Kochō Kanae is dumbfounded at hearing your words, she nods then laughs and calls you a big boy.]
[Due to the arrival of the demon, your experiment has officially begun, and you have experimented repeatedly with your own theory regarding the demon.]
[You will be very happy if the theory is confirmed, but you will be very frustrated if you fail, thinking about what you lost.]
[During that period, Aoi Kanzaki also took the initiative to ask to come to your side to help you, and helped you a lot.]
[During this period, you didn't go anywhere except to heal the injured Demon Slayer Corps members and Kanao Tsuyuri. You concentrated on researching the method of turning demons back into humans. You encounter many difficulties along the way, and you realize that things are not as simple as you think]
[While you were in trouble, lord Kagaya Ubuyashiki suddenly invited you to the Demon Slayer Corps headquarters. You were very confused, but decided to go anyway.]
[When you came to the Demon Slayer Corps headquarters, you saw an unexpected person, or rather a demon. And it was the only demon in the original book that escaped Muzan's control, Tamayo.]
[ Seeing Tamayo, you immediately understand the purpose of Kagaya Ubuyashiki calling you here, because Tamayo is not only an ordinary demon, but also a doctor with excellent medical skills, which makes you very excited.]
[In the original book, she brought Muzan a lot of trouble through his medical skills, which is incomprehensible. You scold yourself for not thinking about this person because you focused too much on research, and wasted so much time.]
[From Kagaya Ubuyashiki, Tamayo is very surprised to learn that you are actually researching a drug that turns demons back into humans, since this is also what she does, and for a while, Tamayo cannot help but have a strong interest in you.]
[ You and Tamayo benefit a lot through communication. Tamayo was also surprised by your medical understanding and received countless inspirations. In this meeting, the two of you spoke very happily.]
[ After returning to the Butterfly Mansion, you excitedly started experimenting. After working hard for some time, you succeeded, but not completely.]
[You have succeeded in making the demons no longer depend on eating human flesh. And can live normally even without the need to drink human blood. But you haven't found a way to completely turn the demon back into a human, nor have you solved the demon's instinct to eat humans.]
[ You think this isn't considered a success. Since you want to do it, you must have to get the best. You believe that since there is a way to turn humans into demons in this world, there must be a way to turn demons back into humans.]
[Your research results are passed on to the Demon Slayer Corps, surprising everyone. Some people think that you can't be trusted to be able to do this.]
[ Tamayo was also very surprised when she heard the results of your research, secretly putting aside her years of research on the method of turning demons back into humans, and started to focus on medicine to suppress demon's blood damage, as she believed you would be able to succeed.]
[ Aoi Kanzaki also looks up to you a lot. She thought that you would definitely become the hero who ends all demons in the future.]
[After a few days of trying, you failed again, the experiment yielded no progress, and you couldn't find any clues, which made you very depressed, and felt that the research progress had hit a bottleneck.]
[On this day, you didn't conduct an experiment, but fell into a depression in the Butterfly Mansion, and accidentally found a little girl with three cherry pink long braids. Sticks its head into the Butterfly Mansion, and you call out to stop it.]
[She's surprised by you, and turns around with a shy expression on his face. You are also surprised when you see it. From a developmental point of view, even though this little girl was not very old, she had developed very well. That's good, lots of adults but no body size adults.]
[ The little girl told you that her name is Kanroji Mutsuri.]
[You nod and ask him what Mitsuri Kanroji is doing here, and she tells you that she's looking for a child, because everyone says that child is very strong, so he's very, very curious, and wants to see what that child looks like. that strong.]
[ You were so speechless, you ignored Mitsuri Kanroji, and chose to turn around and leave.]
[But Mitsuri Kanroji ran directly to catch up with you, looking at you from time to time, and as time went on, his eyes became more and more bright, and she even spoke in front of you.]
[ "Hey, you are so cute! What is your name?"]
[ "..."]
[Kitahara Hakushu's mouth twitched, she ignored Mitsuri Kanroji, and kept thinking about the experiment in her mind, Mitsuri Kanroji didn't feel pressured even if you ignored her, but kept wanting to talk to you and you just ignored everything.]
[During lunch, you discover that Kochō Kanae has prepared rice for Mitsuri Kanroji, and only then do you find out that Mitsuri Kanroji is a guest of the Butterfly Mansion.]
[Mitsuri Kanroji's appetite is terrible, it's as if his stomach has no bottom and she loves to eat. You are speechless when you see her, and feel that her body is too unique. As you thought of this, your expression suddenly froze, and you finally realized where you went wrong!]
[ Right, even though you've done a lot of experiments on demons, you haven't comprehended the human body other than demons. If you don't understand the human body, how can you turn a demon back into a human?]
[Thinking about this, you are very excited. You looked at Mitsuri Kanroji with bright eyes. A demon's body is several times stronger than an ordinary person's body. Naturally, the ordinary human body is difficult to use as a reference.]
[But Mitsuri Kanroji is different. His muscle density is eight times that of an ordinary person. It can be said to be the best reference object. You want Mitsuri Kanroji to accompany you on the experiment.]
[Mitsuri Kanroji is slightly embarrassed by your gaze, and she stops eating. She doesn't understand that you, who was indifferent just now, would suddenly look at him like this.]
[In order to trick Mitsuri Kanroji to the operating table, you start fooling Mitsuri Kanroji madly, telling him clearly the advantages and disadvantages, and then start luring him, saying that if you agree, you can give him an unlimited amount of delicious food.]
Mitsuri Kanroji was dizzy, and didn't understand what experiments, data, and research you were talking about.]
[ He just looked at you and asked curiously: "If I promise you, will we be friends?"]
[ You froze for a moment, and quickly replied: "Yes!"]
[ "Okay, then I agree, from now on we will be friends."]
[Mitsuri Kanroji nods, with a cheerful smile on his face, then continues eating happily.]