In a time when the great war between five rival races for supremacy on Earth ended with humanity's victory led by the hero Sid, the world suddenly gets "overwritten" right before the eyes of a boy named Kai. In this rewritten world, Kai witnesses humanity's defeat in the war as a result of Sid's absence—where dragons and demons now rule the land, and Kai himself has become a forgotten existence to all humans. However, after encountering the mysterious girl Rinne, Kai resolves to break free from this rewritten fate. In a world without a hero, he inherits the sword and martial skills of the hero (Sid) and challenges the powerful enemy races that dominate the land.

Will Serfort dreams of keeping his promise to a childhood friend by becoming a Magia Vander, one of the mighty magicians who sit atop the Wizard's Tower. However, he is unable to cast even the simplest of spells, leaving him to fight dungeon monsters to earn credits at Regarden Magical Academy. As if that weren't enough, he finds himself putting his sword skills to the test against a bullying professor!

Under the tutelage of the great demon warlock Romberg, Ike grew up with knowledge regarding an ancient advanced civilization that once ruled the land. Coupled with his innate talent in magical arts, this upbringing allows Ike to quickly rise in the Demon Lord's army ranks, leading his brigade to consecutive victories against humans. However, Ike has a secret—he is a human himself. Despite knowing all too well the consequences if this information is ever to leak, Ike is willing to face such immense danger to achieve his goal: find a way for humans and demons to coexist and stop the war that has been carried on for far too long.

Abruptly catapulted into a fantasy world, Mimori Touka and his classmates have been summoned by the world’s resident goddess to serve as heroes. Luckily, most of the students display amazing skills upon arrival—except for Mimori, whose abilities bottom out at a measly E-rank. With no further use for him, the goddess banishes Mimori to a dungeon from which no one has ever returned alive. Yet, as it turns out, Mimori’s skills aren’t so much worthless as they are abnormal. Abnormally powerful, even. If Mimori can only claw his way back to the surface, nothing will stand in his way from getting revenge.