Read manga: Dog Days

manga
Summary:

Republic of Biscotti faces a predicament by the invasion of Galette Leo Knights. In order to save the country, Princess Milchore summons a "hero" from the outer world. Shinku, a junior high school boy living in the Earth, is chosen as the hero.

*This series contain side stories to the anime series that take place before the series, in between some episodes and at the end.*