An unknown boy has defeated the Demon King and saved the world, yet he has no memory of his heroic deed or even of himself. As the world eagerly awaits the revelation of the savior’s identity, the amnesiac hero awakens to find himself in a bewildering situation: two different individuals appear before him, each claiming to be his family. This "dramatic fantasy" shifts the focus from the external battle against evil to an internal and deeply personal struggle. The narrative follows the hero, known as Sonata, as he tries to uncover the truth about his past and his genuine connections in a world that sees him as a legend he can no longer remember. Unlike a traditional epic, the story takes an introspective look at heroism, identity, and the fragility of self, as Sonata must navigate the conflicting claims of those who profess to know him best while grappling with the secrets buried in his forgotten past. The series has been noted for its mature emotional construction and its central mystery, which involves the true nature of the hero's relationships and what his victory really meant. The manga moves toward a decisive climax as these long-buried secrets about Sonata’s past and his supposed familial bonds are on the verge of being resolved, leading to significant and unexpected twists.