The Demon King plotted to conquer the world.

To counter this, humanity summoned a Hero from another world. Furthermore, the kingdom's strongest mage and priest were selected as companions to support the Hero, providing full-scale assistance.

—With this, the Demon King will be defeated.

Everyone believed so.

However, the summoned Hero, Toru Kamishiro, was an existence that far exceeded anyone's imagination.

Swordsmanship, magic, intellect—everything was off the charts.

Possessing enough power to defeat even the Demon King's top generals alone, his companions would jokingly say,

"Maybe Toru could just do this alone..."

He was a Cheat Hero of that caliber.

Meanwhile...

In the Demon King's army, there was a high-ranking officer named Guest.

The army's premier brainwashing mage.

Freely manipulating hypnosis and mental domination, Guest enjoyed subjugating various races and turning them into personal "pets."

One day, a direct order was issued by the Demon King.

"Brainwash the Hero's party and make them defect to our side."

Guest accepted with a lighthearted response.

Brainwash the Hero's party and bring them into the Demon King's fold.

Guest thought it would be a simple mission.

However... Toru was prepared for the worst.

He had equipped not only himself but also Laa and Noah with a rare magical item called the 'Mirror of Reflection,' which reflects mental interference back at the caster with double the intensity.

Unaware of this, Guest strolled right up in front of the heroes and—

Guest cast a brainwashing spell so powerful that even Guest couldn't withstand it—