Demon Slayer: Kimetsu no Yaiba: Hinokami Flames

Prelude: Tengen Uzui

While the Demon Slayer Corps were at war with the demons, another faction have appeared. The Shinobi, a group that moves in the shadows. They were never ally nor enemy to anyone. But there were many factions. Around the time of the Edo Era, the Shinobi were wiped out. Or so all of Japan thought.

As the centuries go by, a small clan of Shinobi stayed hidden from the world staying alive, the Uzui Clan. Reaching the Taisho Era, the family strived of nine children, with the oldest being named Tengen who has reached his father's expectations. He has completely mastered the way of the Shinobi when he turned 12, being his father's greatest weapon.

As he reached the coming age of 15, Tengen was approached by his father and three women.

"As you are aware my son, now you are to be married to three women to ensure your linage." Tengen's father told him. "Now then, you two, approach my son." Two women stood up and walked towards Tengen. One was wearing lavender clothing who had her hair in a ponytail, and the other who has the same clothing that was red and had black hair with golden bangs.

"These two have agreed to an arranged marriage to you. They shall serve you well."

Tengen viewed the two. "What are your names?"

"My name's Hinatsuru. We shall follow you."

"I'm Makio. I will follow every order. Even if it means death."

After hearing that last comment, Tengen was feeling concerned about this. The he looked over to the small girl who looked very shy with a blue shinobi dress. "Father, you said I'm supposed to marry three wives. And yet these two are arranged. What about her?"

"She volunteered out of her own free will. When I announced that she would be one of the candidates, she spoke out. She felt the most excited to getting married for some reason."

'I think I can guess what one of those reasons are.' Tengen. "So, then your name?"

"I am Suma! I couldn't be happier to marry a man like you!"

As he grew up, his father forced his children to kill each other, as they have their heads and faces covered so they wouldn't know their opponent was. By the time Tengen learned the truth it was too late. The only ones left standing were him and his younger brother. Looking in his eye, he saw nothing but his father's teachings. He taught them that killing innocent lives would keep the clan safe and provided offspring to keep his methods alive. Shocked by this, Tengen was angry at his father for his betrayal but could not find it in him to kill either of them. Instead, he and his wives left the village, seeing how far down the Shinobi have gone.

"So, you wish to save lives do you not?"

After many days of travelling, Tengen and his wives found the mansion of Kagaya Ubuyashiki who leads the Demon Slayer Corps. "Yes. I've heard many stories about the demons. I even found a village slaughtered by unknown causes. We wish to put our abilities into protecting civilians."

"Then participate in Final Selection and come see me again when you feel ready."

After meeting with him, Tengen participated in Final Selection and survived, earning him the title of demon slayer and his Nichirin Blades.

"Now that we've been accepted into the demon slayer corps, you are to think about your own lives first." Tengen ordered them. "Your lives are top priority in your missions. Don't worry about what's been done. Just ensure that you return to my side. I know it's weird despite your training and professionalism but forget everything they put into your head. You are to live in the flashiest way possible. First you worry about yourselves. Second, the people. You'll save as many people as you can. And finally, myself." The young women were surprised. "As the only one of us four in the demon slayer corps, I'll be the one protecting the ordinary people. I may be the flashiest, but I'll prioritize you three over everything. So, don't get yourselves killed."