With no magic but plenty of physical might, Mash makes it his goal to outdo his magic-wielding classmates to attain the title of Divine Visionary.

Fourteen-year-old Suzuki Iruma has just been abandoned and sold to a demon by his irresponsible parents! Surprisingly, the next thing he knows he's living with the demon who has adopted him as his new grandson, and has been transferred into a school in the demon world where his new "demon" grandfather works as the principal. Thus begins the cowardly Iruma-kun's extraordinary school life among the otherworldly as he faces his true self, takes on challenges, and rises to become someone great.

Meliodas and his friends jump back into action when the new era of peace is threatened by a powerful magical alliance that could spell the end for all.