Dog Days, an anime series, takes place in Flonyard - an alternate version of Earth where humanoid creatures have animal tails and ears. The Republic of Biscotti, inhabited by dog-like beings, is threatened by the invasion of Galette Leo Knights, a group of cat-like soldiers. Princess Millhiore reaches out to another world for assistance and summons a regular middle school student from Earth, Cinque Izumi, to rescue her people by becoming Biscotti's champion. After accepting the invitation to aid Biscotti, Cinque attains a sacred weapon known as the Palladion and prepares himself for the upcoming battle. In Flonyard, wars take place like sports games without any harm being inflicted, and the profit generated serves as a means of financing participating kingdoms. As Biscotti's hero, Cinque performs admirably, but he soon discovers that he is unable to return home after being summoned. Despite the predicament, Cinque promises to continue serving as Princess Millhiore's defender, fighting for Biscotti until the researchers can help him find his way back home.