There was once an ogre (oni) mother who gave birth to a human looking child. Instead of an ogre's horn, this child was born with a sword in hand called the Onikirimaru or Ogre Slayer. He has no name and is only referred to by the name of his sword. Though he appears human, he is pure ogre. Believing that he will become human once all of his kind have vanished from the world of humans, he sets out on his destiny to slay all of his kind. Even now, in the mother world of Japan, he is still out there slaying ogres. (Source: ANN)

Due to his father's job, 15-year-old Hiroshi Kuzumi and his family move to the mountain town of Jouga. While some teenagers might have to worry about fitting in or feel out of place in a new environment, Hiroshi is welcomed enthusiastically at school by most of his new classmates. In fact, it seems like they just can't get enough of him, and he makes two friends rather quickly: the clingy and overly-affectionate Isuzu Tsumuhana, who is also his neighbor; and Kaname Asagiri, who also recently moved to Jouga. All in all, Hiroshi's new life seems to be quite normal—until people start disappearing. Hiroshi is told that the missing townsfolk have simply moved away or suddenly transferred, but he can't shake the feeling that something is wrong. Meanwhile, in the dead of night under a red moon, masked individuals led by a girl with a scythe stalk their prey in the darkened streets of Jouga. Who are they, and are any of the residents safe from their wrath?

After receiving a flyer from Maina Ichii—a member of the idol group ChamJam—and seeing her perform at a local concert, Eripiyo falls in love with Maina and decides to devote her life to supporting the shy and reserved rising star. Eripiyo's charismatic presence and iconic red tracksuit soon give her recognition as Maina's one and only unrivaled fan. Whether it be a performance or a small fan gathering in the middle of nowhere, Eripiyo is guaranteed to be at every event Maina participates in. Not even an injury or Maina's seemingly cold attitude toward her can stop Eripiyo from pursuing her dream of seeing her beloved idol perform at the world-famous arena Budoukan.

Twintails: the glory of all mankind—or at least that is what first-year high school student Souji Mitsuka believes. At school, Souji spends most of his time daydreaming and rating girls' twintails, even going as far as creating a club dedicated to the hairstyle. His obsession does not go unnoticed, however; when monsters from outer space attack Earth and claim the world's twintails for themselves, a strange woman named Twoearle enlists Souji to fight back using twintails of his own! By transforming into the twin-tailed warrior Tail Red, Souji combats the vicious alien organization known as Ultimegil, whose main goal is to colonize Earth and steal everyone's spiritual energy, or attribute power. Alongside fellow twin-tailed fighters Aika Tsube and Erina Shindou, Souji must find a way to defeat the invading army and defend the twintails he holds so dear.