In a world on the verge of a great disaster that began five years ago, heroes who, with the help of a device called HxEros, use the power of Ecchi (H) and erotic power (Ero) to save the planet from libido-devouring monsters! Enjou Retto and Hoshino Kirara are childhood friends who have drifted apart from each other. One day, they're caught in a battle against a "Censor Bug" that feeds on human's sexual energy to evolve. After successfully taking down the enemy, they join a group of heroes like them, using the erotic power of the HxEROS force to fight off monsters. (Source: MU)

In the distant past, a war between humans and demons brought about widespread chaos and bloodshed. To put an end to this seemingly endless conflict, Demon King Anos Voldigoad willingly sacrificed his life, hoping to be reborn in a peaceful future. In preparation for their king's return, the demon race created the Demon King Academy, an elite institution tasked with determining Anos' identity when he reawakens. He reincarnates two millennia later, but to his surprise, he soon learns that the level of magic in the world has drastically waned during his absence. Moreover, when he enrolls at the academy to reclaim his rightful title, he finds out that demonkind remembers him differently. His personality, his deeds, and even his legacy are all falsified—masked beneath the name of an impostor. This "lack" of common knowledge renders him the academy's outlier—a misfit never before seen in history. Despite these drawbacks, Anos remains unfazed. As he sets out to uncover those altering his glorious past, he takes it upon himself to make his descendants recognize that their ruler has finally returned. [Written by MAL Rewrite]

The legend of the Divine Gate is a story told to young children that depicts the merging of the living world, the heavens, and the underworld. "Adapters"—people born with unique elemental abilities gifted to them from the union of these worlds—formed the World Council, an organization which controls the chaos of the Gate by portraying its legend as nothing more than a myth. These Adapters train in a special academy owned by the World Council that allows the students to hone their skills. Aoto, a teenage boy with exceptional water powers and a tragic past, rejects the offer to join the academy numerous times—until he is successfully pressured by the energetic wind user Midori and stubborn fire user Akane. Together, with the World Council and their mysterious leader Arthur, they seek out the Gate in the hopes of uncovering the truth. But in order to reach their goals, they must unite and overcome their own despair while dealing with behind the scene mischief. [Written by MAL Rewrite]

Yuuta Hibiki wakes up in the room of Rikka Takarada and notices two things: he has no memories, and he can hear a mysterious voice calling his name from a nearby room. On further inspection, he finds a robot—which introduces itself as Hyper Agent Gridman—behind the screen of an old computer. Much to Yuuta's surprise, Rikka cannot hear Gridman, nor can she see the ominous monsters looming over a thick fog as it envelopes the town outside. Another giant monster materializes in the city and proceeds to wreak havoc. Amidst the confusion, Yuuta is once again drawn to the old computer and merges with Gridman. Suddenly, he appears in the middle of the battle and is forced to fight the monster. Together with Rikka and fellow classmate Shou Utsumi, Yuuta forms the "Gridman Alliance" to defeat the monsters plaguing the city and find whoever is responsible for their emergence. [Written by MAL Rewrite]