"Unreliable compared to our era," "Is he truly the Hero's son?" — he was sick of hearing it.

Over a decade after the war between humanity and the Demon Lord ended, the children of the Hero and his companions, the heroes who saved the world, had grown up.

One of them, Earth, was a prodigy. Everyone expected him to follow in his father's footsteps and become a magnificent warrior protecting the nation, but Earth was exasperated by the ever-present burden of his father's title.

Then one day, Earth was stunned when he saw his father's sword—the one that had defeated the Great Demon Lord—sealed away in his family's mansion.

Because there, unable to find peace and lingering in the mortal realm, was the ghost of the Great Demon Lord.

For some reason, only Earth could see the Great Demon Lord's spirit, and what's more, the Great Demon Lord possessed Earth from within the sword.

Forced to spend every moment with the Great Demon Lord's spirit, as they lived their strange cohabitation, the Great Demon Lord whimsically whispered to Earth:

"I hold a grudge against your father. If you wish to prove your father and the world wrong, I shall train you. I'm bored anyway."

Solely to prove his parents and the world wrong, Earth begins to receive special private instruction from the Great Demon Lord.

And on that fated day, his Heroic parents, the former heroes, his first love, his childhood friend the princess, his genius peers—and the entire world—will be shaken to their core.

【May 21, 2019: Achieved #1 Daily Overall Ranking】

【December 14, 2019: Volume 1 of the novel released by Earth Star Novel】

【March 14, 2020: Volume 2 of the novel released】

【April 2, 2020: Manga adaptation Chapter 1 begins on Earth Star Comic's official website】

※This work is also posted on Kakuyomu.