After the great battle between the Demon King and the Hero, justice prevailed and the devils scattered. The Demon King was killed. A few years later, the Demon King's daughter went on a journey to find her father's heritage, and met the granddaughter of the Hero.
The Hero's Granddaughter and the Demon King's Daughter is a completed manga by Fudou Ran, first published in 2017. It blends action, adventure, girls' love and drama. You can read all 21 available chapters of The Hero's Granddaughter and the Demon King's Daughter online for free on MangaPulse; the newest is Chapter 20, added 2025-03-16. The series is finished, so you can read it from start to end in one go.