The Nocturnal Community Relations Division is a team of people who specialize in solving cases involving the ominous occult creatures of the night unseen by ordinary humans. Young and unsuspecting Arata Miyako has been assigned to the Shinjuku Ward Office of the division, where he meets his fellow members Theo Himezuka and Kyouichi Sakaki. On his first night, Arata finds himself on a mission where he discovers to his surprise that not only does every supernatural creature he once thought to be fictional actually exist, but also that he is the only human who can understand their non-human speech. Arata's surprises do not end there, as later that night, he meets a legendary creature called a Tengu that refers to him as the famous Heian-era exorcist, Abe no Seimei. Unfamiliar with the exorcist, Arata pays no mind and continues to work with his team, utilizing his unique ability to assist in the resolution of their cases. Mistaken by many occult creatures as Abe no Seimei and quickly becoming notorious for his special ability during his work, Arata becomes curious of his origins and invests himself more into solving cases regarding occult creatures he encounters once he learns of a certain connection between himself and the exorcist. However, Arata will quickly find that dealing with supernatural creatures is not as simple as he thought, as danger begins to play a fundamental role in his everyday findings and his ability starts to present an unexpected issue.

Takumi Tsuzuki is a high school student who attends the Umenomori Private Academy, free of charge, alongside Fumino Serizawa, a childhood friend of his whom always says the opposite of what she feels. He spends most of his time at school fending off Chise Umenomori, the granddaughter of the board chairman and a pampered princess, who is constantly roping him into her eccentric hobbies. After school, he goes to work at the "Stray Cats" confectionery, a cake shop run by his adoptive older sister, Otome Tsuzuki, until it's time to go to bed. This is the average routine in the day and the life of Takumi. Mayoi Neko Overrun follows another seemingly average day in the life of Takumi. With his sister away from the shop, having gone to save someone else in need of help, Fumino takes it upon herself to wake him up so that he won't be late for their usual walk to school together, giving him a glimpse of her blue and white striped panties in the process. What a nice way to start the day. When Otome returns home, she brings with her a girl named Nozomi Kiriya, whose hair and mannerisms resemble that of a large cat. It turns out that she is a runaway that Otome can't help but take in. Takumi's ordinary days are transformed into splendid chaos as he tries to unravel who this mysterious beauty is and what she's running away from...

Rumor has it that if a young girl strikes a bargain with a white fairy, it will grant any wish her heart desires. However, in exchange, she will become a magical girl and must put her life on the line to slay fearsome and ferocious witches. Iroha Tamaki, a kind-hearted middle schooler from Takarazaki City, is living proof that these rumors are true. Armed with a magical crossbow and the ability to heal injuries, Iroha seeks out the labyrinths where witches hide and defeats them before they can prey on humans. Yet Iroha has no memory of her wish, and even Kyuubey, the white fairy himself, seems to have no idea what Iroha requested of him. One day, Iroha hears rumors of a city where "magical girls can be saved," and finds herself on a sunset train to Kamihama City. Unfortunately, she discovers that the witches in Kamihama are far more powerful than usual. After veteran magical girl Yachiyo Nanami is forced to save her, Iroha vows to never return. But when a chance encounter with a tiny Kyuubey seems to trigger distant memories, Iroha is compelled to investigate the mysterious city despite the danger. [Written by MAL Rewrite]

After Keita Suminoe's mother passed away, his father promptly remarried, introducing two step-sisters into Keita's life: twins Ako and Riko. But since their fateful first encounter, a surge of incestuous love for their younger brother overcame the girls, beginning a lifelong feud for his heart. Now at the end of his middle school career, Keita studies fervently to be able to attend Ako and Riko's high school. While doing so however, he must resolve his conflicting feelings for his siblings and either reject or succumb to his sisters' intimate advances. Fortunately—or perhaps unfortunately for Keita—his sisters aren't the only women lusting after him, and there's no telling when the allure of temptation will get the better of the boy as well. [Written by MAL Rewrite]