A young man from the modern era travels to the Demon Slayer world and becomes the descendant of Tsugakuin Yoriichi – Tsugakuin Najo. The protagonist is born with markings and natural transparency. There are two female protagonists (guess who they are): Muzan: "Don't come over here!" Kokushibo: "Come on, you will finish Yoriichi's unfinished duel!" Sango: "The ultimate battle!" (Slightly altered plot) (This book is not a cool novel; just having markings and transparency doesn't mean you can easily kill an Upper Rank! It's a coming-of-age novel.)

Ever since the Breathing of Fire was developed during the Warring States Period, more than 80% of the Flame Pillars have carried the name of Purgatory.

Even Rengoku Kyojuro, the last Flame Pillar of the Taisho period, gave up his own dawn for the dawn of others.

But if history diverges,

That one,

It keeps growing upwards,

The flower called "Purgatory"

Inadvertently, a fruit was born, but it was helplessly abandoned. Who can guarantee that it will sprout again as a seed in the shade and grow in a deformed form...

Or will it just be a fallen petal, transforming into nutrients to dedicate itself to the growth of future generations...

(I write simply because I feel like writing. My writing may not be good, and the updates may not be on time. After all, I am also a quasi-working person.)

What if you encounter Muzan at the start and become a demon? Before you lies the demon who doesn't eat humans, the heir to the Forest Breathing, the Pillar who strikes fear in countless demons, the honorary founder of the Butterfly House, a staunch supporter of Dorayaki, the poop-scooper of Shiba Inu Enji, the idol of the male and female members of the Demon Slayer Corps, and the trusted senior of all the Pillars: the Forest Pillar - Moriki Shinichi! [Not a system! Not a cool story! Growth-oriented! Single female protagonist! Don't read if you mind, the author is sensitive, so please don't criticize if you don't like it.]

(Pseudo-invincible + female lead Shinobu Kocho + system runs away at the start) Shimotsuki Mirai transmigrated to the present day and has spent her childhood wandering around the forges of the sword-forging village, the clanging of hammers the lullaby of her life. The blacksmiths always said this child's eyes were too still, as still as a quenched blade, unaware that the vermilion burn marks on his palms, shrouded in years of wear, concealed an astonishing power no less than that of a Nichirin Blade. When he first met Shinobu Kocho, he only felt a stinging pain in his eyes. Before seeing the girl, all his information about her came from the precious little black box he couldn't bear to part with in his previous life, but now, the person from his dreams stood before him, more vivid than any description. The girl blushed, staring at the light dancing on his fingertips, asking if he was a deity descended to earth. Kanae leaned against the door, chuckling softly, "Such a wondrous boy is hidden in the sword-forging village." Looking into the clarity in the girl's eyes, Shimotsuki Mirai suddenly wanted the sword in his hand to protect that light a little longer, just a little longer...

No heroine, no CP, not dark, not saintly

Traveling back in time to become Muzan five hundred years before the story began?

There is a lot of room for operation!

Blue spider lily! Overcome the sun!

Become the ultimate creature!

Living with the Twelve Ghost Moons (bushi)

Scare the Demon Slayers from time to time, and also play undercover (ಡωಡ)

Live until cell phones appear!

Games! Novels! Anime!

even……

Met the original scumbag boss, standing in the sun and shaking his head to mock him~

Let me know who the next victim will be (ಡωಡ)

[Rating just came out!! It will gradually rise!!]

[Pure villain + pure evil + cannibalism + invincible + no system]

Kurokawa, a sickly man coughing up blood every day, has been surrounded by malice since birth because of the twisted lines on his back. His only sister, who loved him, was burned to death by the villagers while protecting him.

In his deathbed despair, Muzan, lurking in the shadows, offered him a way out.

The demon blood enters the throat, awakening the seven aspects of the Blood Demon Art.

Pride, envy, wrath, sloth, greed, gluttony, lust

This filthy world is disgusting!

I will judge your crimes!

Evil spirit + joins Muzan + eats people + no system.

(The protagonist is very bad! Very bad! No humanity, please don't mind if you accidentally enter!)

Manami, who depended on his younger brother for survival, joined the Demon Slayer Corps and became the disciple of Yoriichi Tsugukuni, the most powerful member of the Demon Slayer Corps. However, he failed to kill Muzan during an encounter with him, and thus became a sinner of the Demon Slayer Corps. He was expelled from the Demon Slayer Corps along with his master Yoriichi Tsugukuni.

When he met Muzan again, he had two choices: become a demon and make those who hurt him pay the price, or continue to live like garbage.

Wan Mi chose the former.

Since you have expelled me, I will live my life in the most horrible way possible!

If the Demon Slayer Corps can't tolerate me, then I will become an evil demon!

Luochuan woke up and came to the world of Demon Slayer.

Together with Zenitsu, he was picked up and raised by the Pillar Jigoro Kuwashima.

However, he did not have the talent to practice breathing techniques, so he could only learn Thunder Breathing from Zenitsu.

Just when Luochuan was thinking about how to survive in this world full of ghosts, Luochuan awakened the friend system!

As long as you become friends with the other party, even if it's just verbal, you can get various rewards!

Add Zenitsu as a friend and receive the reward of Lightning Breathing Type 1: Thunderbolt Flash!

Add Tanjiro Kamado as a friend and receive the reward "Thread of Gap"!

Add Lei of the Lower Five as a friend to receive a bonus Blood Demon Art line rotation!

Add the Flame Pillar as a friend and receive the reward of the Secret of Breathing of Flame: Type Nine: Purgatory!

"No, you are full of blood demon arts, you say you are a Hashira??"

Su Chen traveled through Demon Slayer's Spider Mountain and almost got killed as he landed.

At the critical moment, he awakens the golden finger and has an incredible understanding.

In the end, he was injured and rescued by Shinobu Kocho and became a member of the "Butterfly House".

Su Chen goes out with Shinobu Kocho to rescue people during the day, and secretly kills ghosts at night to make money to support the girls in the Butterfly House.

While walking, constantly use the golden finger to observe and learn.

[You observed Shinobu Kocho's healing process and gained something from it. You created your own skill: Supreme Poisonous Healing!]

[You observed Kanao's sword training and suddenly an idea struck you, revealing a unique sword technique. A thought blossomed!]

You spied on the former Sound Pillar's thunder cry, gathering mosquitoes into thunder. Deeply impressed, you modified it slightly and developed the Lightning Release - Chidori Style!

From then on, Butterfly House had a famous and evil male doctor.

When everyone asked Su Chen why he worked so hard, Su Chen's thoughts were very simple.

"Why kill ghosts? Of course, it's to keep the flowers in the Butterfly House working well and feeding them!"

After traveling through Demon Slayer eighteen years ago, Kamishiro Mitsuteru thought this was just an ordinary ancient world.

Until the night of the blood moon, the evil spirits tore his warm home apart.

When you are on the verge of death, the sign-in system is activated!

[Congratulations to the host for receiving the Newbie Gift Pack: Nature-type Sparkling Fruit! ]

The body instinctively transforms into elements to avoid the fatal blow!

He raised his hand and pointed, and the holy light penetrated the evil ghost, evaporating it instantly!

The loud noise attracted the dying Kanae Butterfly, and the Second Upper Moon, Douma, who was standing in front of her.

Under Kanae's desperate gaze, Kamishiro Kouki transformed into a beam of light and kicked Douma half of his body away at the speed of light. He sneered and said, "Sorry to bother you. But you can die now."