A young man finds himself reincarnated as Leirus, a boy believed to be destined to defeat the demon king and achieve heroism - or so he assumes. However, he ends up in slavery and comes to terms with his impending death. At the age of fifteen, he narrowly escapes an attack by a chimera while being taken to a mine. Alone and starving, he is unexpectedly rescued by Corona, the compassionate daughter of a dining hall proprietor. Leirus embarks on a journey as an adventurer and experiences human kindness for the first time. Yet, his newfound sense of safety is fleeting, as the chimera he once evaded comes back to pursue him. To repay those who have assisted him, Leirus must face his former adversary and rise to become the hero he was destined to be.