In a high school where history lessons drone on without practical use, a bored student named Mari is suddenly thrust into the past by a mysterious force. She finds herself walking alongside iconic figures from Japanese history, from the warring states period to the Meiji Restoration, only to discover that these legendary heroes and villains are far less competent than the textbooks suggest. Oda Nobunaga cannot strategize his way out of a simple board game, Tokugawa Ieyasu spends more time complaining about his health than unifying the country, and Sakamoto Ryoma invents devices that always break at the worst moment. Each short episode follows Mari as she tries to survive historical events while the great figures bumble through their own legacies. The series moves through a rapid succession of eras, including the Heian period with a vain and poetry-obsessed Minamoto no Yoshitsune, the Sengoku period where battles devolve into petty squabbles, and the Bakumatsu era featuring a perpetually confused Shinsengumi. Notable arcs include Mari’s repeated attempts to return home, which are consistently sabotaged by the very historical figures she hopes will help her, and a running gag involving a time-traveling convenience store that appears in every century. Despite the chaotic and often useless advice she receives, Mari gradually learns that history’s true value might not lie in grand strategies but in the absurd, human moments that textbooks leave out.