Dog Days centers on Cinque Izumi, an ordinary middle schooler unexpectedly summoned to Flonyard, a fantastical world where people have animal features.
He's called upon by Princess Millhiore of the dog-like Republic of Biscotti to defend them against the feline Galette Leo Knights.
These conflicts, however, aren't deadly wars but are instead more akin to sporting events.
Cinque takes up the role of Biscotti's champion, but soon discovers he can't return home easily.
He must then continue to aid Princess Millhiore as they try to find a way for him to go back to Earth.