What Is The Origin Of 'Demon Slayer: The Demon King'S Sword'?

Being the only child to the Queen of Castle Grey, lost within the confines of mount Trenon, Kilvic is made to learn a number of things best suited to the heir to the Elzcrid bloodline at the hands of tutors handpicked by his mother. However, his fifteenth birthday sends him beyond the reaches of his mother’s domain. She has tasked him with the duty of learning more. Understanding greater things than she can teach him, greater things with which to cope with the curse upon his bloodline as she had been taught by her father and mother. Finding himself in a new kingdom, in an academy designed for only the most elite of mages, Kilvic is tasked to survive the new things he will come to learn, while struggling with the chaos of human association, as he comes to understand that while he may know a great deal about the world from the castle archives, it is a different thing to experience them. The association between people isn’t as easily deciphered as the books made them seem. As he struggles with the task of becoming a mage and a student along with surviving new friendships, failure threatens him at every turn and people prove pettier than the books would have him believe. Yet, despite all these, somewhere hidden in the shadows of the kingdom, a creature stirs, taking from the academy the one thing it values most. Kilvic must survive the trials of the academy, keep his friends, best his first enemy, and ensure that what stirs must not cause more damage than the kingdom can bear, lest the supremacy of Castle Grey be called into question in realms beyond that which most know. And all in time to attend the Winter Hall Fest.

Serra is a normal senior high school student who works really hard every night and weekend to pay off her parents' debts from loan sharks. But when she couldn't keep up with payments anymore, she decided to end her life. Surprisingly, she woke up in a different light-- in another world. What's more shocking was when she is addressed by one of the people as the demon king's bride.

Miaka Von Speltsper, the myth, the legend and the daughter of two Gods. Miaka, the Demon King and the head of the Dark Council is the most powerful demon ever known to mankind, but she has a secret. She’s a hybrid. And the world she lives in has hunted down and eliminated every single hybrid in all the dimensions. But now…someone knows her secret, someone who has the power to destroy her. However, the world is changing and one of those changes is Kaleb Takeshi, the man with extraordinary eyes who has stolen Miaka’s heart with just one glance. But there is something about Kaleb that Miaka can sense but can’t describe. And not only is he human, he’s an enemy who has decided to give his loyalty to her. In this world of lies, deceit and betrayal; can Miaka trust her heart or will she have to choose century’s old traditions to stay alive? Because if she dies, it will truly be the end of the world.

She accidentally summoned the great Demon King but all she ever wanted was to get rid of her ghosts. “Can I take it back?” She asked, blinking innocently with her soft long eyelashes. “You’ve sealed the contract with the kiss. There’s no going back now.” A smirk played at his plump red lips.

Her past was a bit of a mystery. A close kept secret that she wouldn't dare utter to anyone. The chance of being vulnerable, to forcing her to actually trust another individual frightened her. Incredibly shy, but a silent warrior who came through with scars and all. She was sure to live the rest of her days alone, only to be captivated by him. Who is he? Can she trust him? Did she want to trust him? Only time could tell.

He died killing the Demon King. He woke up sixty years too early. Now the monster is a young man. And he is running out of reasons to stay away. --- Lysan Dusk was the hero who saved humanity. He killed the Demon King, ended the war, and delivered the world from suffering, and his reward was betrayal. He wakes up in a young student's body in a dormitory room of a magical academy, and the calender shows that the date sixty years before he was born. The world outside hasn't broken yet. The war hasn't happened. Lysan's plan is to keep it that way by staying completely out of it. Fail his combat exams, spend whatever borrowed time he has left, living a quiet life, where nothing requires him to be a hero. The man who will become the Demon King, the most feared monster in history is still young and beautiful, with pale grey eyes that find Lysan across every crowded room like he is the only person worth seeing. Lysan knows what those eyes will become. He has looked into them across battlefields, spent a lifetime seeing them in nightmares. He never expected it to feel like this up close. Roman is everything Lysan was warned about — magnetic, dangerous, impossible to ignore. Everyone except Lysan, refuses to be charmed, refuses to feel anything at all. But now, he is failing spectacularly at them because Roman keeps finding him. Keeps watching him and making Lysan's carefully rebuilt walls feel like paper. Lysan knows the ending. But for the first time in two lifetimes, he is wondering if the ending can change. If the monster can be loved instead of killed. If staying is braver than running.