Warning: The story and summary contains spoilers from the manga. Please read at your own discretion! It is thought that the child of Tsugikuni Yoriichi died along with his wife, but it turns out, the child was able to survive in secret. After finding out their birthright, they embarked on a journey to find the origins of their family. Future generations vowed to never associate with the Demon Slayer Corps due to what they considered a betrayal. Teachings of Sun Breathing have been passed down from generations, but none have strive to be demon slayers as the animosity still remains. Enter Tsugikuni Yui, second youngest of the current generation and born with a different perspective than her ancestors. Going against her family's teachings, she ran away to pursue the life of a demon slayer and hopefully finish the job her ancestors never finished. Along the way she met the person who is to continue Sun Breathing, Kamado Tanjiro. Disclaimer: Demon Slayer plot and characters belong to Koyoharu Gotouge.