The series revolves around Cinque Izumi, a cheerful and athletic half-Japanese, half-English boy studying at Kinokawa International School in Japan who is suddenly summoned to the alternate world of Flonyard. The people there look no different from humans, except for one thing; they have animal ears and tails. The one who summoned him is Millhiore, the dog-like Princess of the Biscotti Republic, who requested his assistance in their war against the forces of the feline-like Galette Lion Army. The wars in Flonyard differ from the ones on Earth, and are waged with special rules and no casualties in a fashion similar to a sports competition with the purpose to raise funds for the Kingdoms involved, where the winner faction claims a larger sum than the losing side.
After winning his first battle for Biscotti, Cinque learns that when a hero is summoned into Flonyard he becomes unable to return to his homeworld, a fact that Millhiore also was unaware of. The scientists of Biscotti promise to Cinque to find a way for him to return home in 16 days, the remaining time until his meeting with his friend Rebecca whom he promised to spend the last three days of his Spring Break with.
The series, produced by Aniplex and Seven Arcs, is directed by Keizo Kusakawa, series compositon by Masaki Tsuzuki, character designs by Osamu Sakata, music by I've Sound, Maiko Iuchi, Susumu Natsume and Yui Isshiki, and produced by PROJECT DD. The first episode was aired on April 2, 2011 on Tokyo MX, Tochigi TV, Gunma TV, Chiba TV, TVK, TV Saitama and Mainichi Broadcasting System, Inc., with subsequent re-runs on Chubu-Nippon Broadcasting and BS11.
Anime sales for Dog Days are very decent. The first season of Dog Days earned slightly over 10,300 DVD and BD sales during 2011. Likewise, the second season, Dog Days', earned 10,500 DVD and BD sales during 2012. To put it in perspective, the majority of anime don't reach this point. While the 'break even' point is slightly less than 3,000.