Kindan Shitei de Breakthrough - Yuusha no Musuko ga Maou no Deshi de Nani ga Warui
Alternative title: A Breakthrough Brought by Forbidden Master and Disciple, A Breakthrough Came Out by Forbidden Master and Disciple., Breakthrough with the Forbidden Master - So What If the Hero's Son Is the Demon King's Disciple, Breakthrough With The Forbidden Master ~What's Wrong With The Hero's Son Being The Demon King's Disciple?~, Eirth, apprenti du Roi-Démon (French), Kindan Shitei de Breakthrough ~Boy Meets Satan~, Kindan Shitei de Breakthrough ~Yuusha no Musuko ga Maou no Deshi de Nani ga Warui~, Verbotene Allianz, Напролом с запретным учителем. А что если сын Героя — ученик Короля Демонов?, Прорыв с запретным мастером, 禁断師弟でブレイクスルー~ボーイ・ミーツ・サタン~, 禁断師弟でブレイクスルー～勇者の息子が魔王の弟子で何が悪い～
Story Overview
Is the hero's son and the ghost of the Demon King a master and disciple? Eirth, the son of the hero who vanquished the Great Demon King, is struggling with pressure. Constantly expected to live up to legendary achievements, he finds himself falling short. No matter how hard he tries or what results he delivers, it's never enough. "I'm a failure compared to my father," or "You're the son of a hero, don't you know?" With this weight on his shoulders every day, Eirth's fate takes a turn when he enters the room that holds his father’s sword. "Interesting. I'll train you. I have nothing but free time now," says the ghost of the Demon King. Eirth agrees to receive personal training from the Demon King, driven by the desire to prove himself and get back at his parents and the world. In the future, his parents, the legendary heroes, his childhood love—the princess, the geniuses of the age, and the world itself will tremble before him.