"Looks like I accidentally married a Rengoku..." "Father will definitely kill me..." Fuyuko Kazahana, a young girl with a tragic pass that she kept as her deepest darkess secret, a sin that she will hold forever even in the afterlife. She enters the world of being a Demon Slayer for her own entertainment and excitement, life is dull for her but whenever she fight, she felt alive. Her cold exterior made her intimidating and cold blooded but Fuyuko is human, who also have emotions. After a plan of hers that gone wrong, she didn't expect to be married to a certain descendant from the clan of flames that had been her father's sworn rival, he hated them very much. But who cares? Fuyuko didn't really care, a certain bright flame brought warmth she never felt and fate unexpectedly turned her world upside-down. Whilst she just go with the flow like a winter breeze.

Cressilyn was nothing extraordinary- just a perpetually exhausted student trying to survive exams, responsibilities, and the relentless cycle of everyday academic life. Then came the classic ending she never expected: one encounter with Truck-kun and everything went dark. When she opened her eyes again, she found herself reincarnated in the world of Black Clover. Armed with fading memories of her previous life and a vague understanding of the future, she plans to keep everything in place where she, as an unknown variable, intends to remain invisible, preserving the future she remembered. Unfortunately, fate seemed determined to place her directly in its path, entwining her fate to the Captain of the Golden Dawn. The moment she met William Vangeance, everything began to change. ⚠️ Spoiler Alert: Future manga events and plot points may be referenced throughout the story.