Professional wrestler Genzou Shibata sports the body of a mountain, but beneath his hulking appearance is a man with an extreme affection for animals. Facing off his opponents in the ring as the legendary Animal Mask, Genzou wins the hearts of crowds everywhere with his iconic tiger persona. During the bout for the title of World Champion against his greatest rival, the Macadamian Ogre, Genzou is suddenly summoned to a fantasy world by a princess. With her kingdom being threatened by a monster infestation, she pleads the wrestler for assistance—to which he answers by knocking her out with a German suplex! Escaping the castle and finding himself stranded in a mysterious land, Genzou decides to begin his career as a beast hunter to capture and befriend creatures far and wide. Joined by the wolf-girl Shigure, the dragon-girl Hanako, and the vampire Carmilla Vanstein, the professional wrestler pursues all kinds of dangerous requests for the sake of fulfilling his dream as a pet shop owner.

Following the revelations of the archangel Gabriel, Ente Isla hero Emilia Justina—who lives on Earth under the alias Emi Yusa—starts doubting the validity of her mission to slay the Demon Lord Satan, now reduced to a modest employee of MgRonald's as Sadao Maou. At the same time, Sadao's high school-aged coworker Chiho Sasaki pursues a new dream with hopes to protect not only herself but also her friends. Secretly training with Emi and Suzuno Kamazuki to develop telepathic powers, Chiho's training is cut short when a group of demons abducts her. As angel and demon attacks threaten the fragile peace between the two worlds, Sadao and Emi need to put their troubled past behind them if they want to have a chance to find their new purpose in life.

The energetic Tapio Chatarozawa and the cool-headed Kuehiko Roshihara are two young cats trying out various part-time jobs. From delivering packages to washing windows on skyscrapers, the pair explore the opportunities that await them out on the recruiting field. As they struggle to learn the ropes, the duo endures the antics of their colorful customers and supervisors while bonding as working buddies.

Inside the human body, roughly 37.2 trillion cells work energetically 24 hours a day and 365 days a year. Fresh out of training, the cheerful and somewhat airheaded Sekkekkyuu AE3803 is ready to take on the ever-so-important task of transporting oxygen. As usual, Hakkekkyuu U-1146 is hard at work patrolling and eliminating foreign bacteria seeking to make the body their new lair. Elsewhere, little platelets are lining up for a new construction project. Dealing with wounds and allergies, getting lost on the way to the lungs, and bickering with similar cell types, the daily lives of cells are always hectic as they work together to keep the body healthy!