In the Flash-animated television comedy series, a sumo wrestler named Mikoshiarashi travels around the world to train to become the Yokozuna, the Grand Sumo Champion. He meets colorful characters along the way as he is determined to meet his goals.

Nanae Island is a man-made island in the Pacific Ocean that holds everything necessary for the proper education and training of children. It was created by the Great Seven, a group of adventurers headed by Nanana Ryuugajou, as a place for the young to chase their dreams. After being disowned and exiled by his family, high school student Juugo Yama arrives on this island, happy to finally be free of his father. Upon moving into his new room, he discovers the ghost of Nanana Ryuugajou, bound to the island after her unsolved murder 10 years ago. Nanana tells Juugo that, just before her death, she hid items with unique and mysterious powers all across the island—items known as the Nanana Collection. Hoping to uncover clues that will help him find the culprit behind her death, Juugo, with the help of self-proclaimed "Master Detective" Tensai Ikkyuu and her cross-dressing maid Daruku Hoshino, sets out on his search. [Written by MAL Rewrite]

Tokine Amino is the young and overburdened secretary of the CEO at a talent agency. One day while cleaning, she is suddenly transported to a strange alternate dimension ruled by a floating piglike creature. The creature, Hacchin, explains that this dimension is called "Quizun," and transforms her outfit before stating that she cannot leave unless she solves a puzzle within five minutes. While Tokine manages to keep a mostly calm composure and solve the puzzle, Hacchin recognizes her talent and decides that the two will meet again. Now Tokine runs the risk of suddenly being transported to Quizun at any time, along with anyone who may be within her vicinity. [Written by MAL Rewrite]

Continuing where the first season left off, the sudden increase of Thanatos with the disappearance of the Aube Hunters has now left Arcadia in ruin. Desperation reigns high as the Religious Organization fights to battle the Thanatos. Six months had already past since Hidamari mansion burned to ashes, the Aube Hunters, once hailed as heroes, is now blamed for the appearance of Thanatos. Nevertheless, hope still exists for the reappearance of the Queen's Egg one day, who will become the savior of Arcadia. Unknown to many however, the Aube Hunters have actually been silently waiting for the awakening of Angelique, who has been asleep the entire time.