Prologue: Inventible Disappearance

While away from his mountaintop home, healthy thirty seven year old charcoal merchant Tanjuro Kamado uses his skills to prevent the sadistic and cold natured demon Doma from killing widowed teen Kotoha Hashibira and brings both her and her infant son Inosuke to the safety of his mountaintop home, where the charcoal merchant introduces them to his thirty three year old expectant wife Kie and their one toddler daughter Sumiko. In response to this, Doma shows up outside the house the following night, sneaking inside through the family's bedroom window and snatching Sumiko from her wooden crib while she, her parents, Kotoha and Inosuke are all fast asleep in the small room. Twenty years later, Sumiko, now a beautiful twenty one year old woman, is taken out of the temple at sundown in the aftermath of a risky mission by the sweet natured twenty five year old Demon Slayer Corps warrior Kyojuro Rengoku, who then lifts her up into his arms and uses his skills to quickly and safely get her back to his family's home while carrying her.