An evil monkey, Specter, has escaped a circus, using a mind-controlling device which allows him to become smarter and have access to controlling the monkeys. Kakeru is called over by a professor in order to capture all the monkeys, including the one's who's controlling them: Specter.

Five supernatural factions have been fighting against each other for who knows how many centuries, with the beginning of Aquarian Age always in mind. Kyouta, soon begins to see visions of mystical girls fighting, except they do exist. Soon he and his girlfriend Yoriko become involved and the battle for Earth and Aquarian Age lies in their hands.

Fubuki Sakuragasaki is a powerful gamer who, with the power of her Passion Panties, climbs up the ranks of the BAG (Best of Arcade Gamer) tournament to become the greatest Arcade Gamer in the world. However, the evil Gulasic Group is out to conquer the world through said tournament, and their gaming skills will prove to be a challenge. Fubuki must team up with the legendary Mr. Mystery to combat the four Gods of Gaming and make the world of arcade gaming safe for all.

Supersonic monkeys, vampires, talking fishmen, and all sorts of different supernatural monsters living alongside humans—this has been part of daily life in Hellsalem's Lot, formerly known as New York City, for some time now. When a gateway between Earth and the Beyond opened three years ago, New Yorkers and creatures from the other dimension alike were trapped in an impenetrable bubble and were forced to live together. Libra is a secret organization composed of eccentrics and superhumans, tasked with keeping order in the city and making sure that chaos doesn't spread to the rest of the world. Pursuing photography as a hobby, Leonardo Watch is living a normal life with his parents and sister. But when he obtains the "All-seeing Eyes of the Gods" at the expense of his sister's eyesight, he goes to Hellsalem's Lot in order to help her by finding answers about the mysterious powers he received. He soon runs into Libra, and when Leo unexpectedly joins their ranks, he gets more than what he bargained for. Kekkai Sensen follows Leo's misadventures in the strangest place on Earth with his equally strange comrades—as the ordinary boy unwittingly sees his life take a turn for the extraordinary.