Sinku Izumi, a young extreme traveler, managed to visit the magical world of Froniard during his spring break. Under a raspberry‑colored sky with flying islands, the spirit of adventure reigns; wars resemble cheerful sporting games, and local beauties all seem perfectly matched with ears and tails! A resident of our world was called a hero—and he became one—quickly resolving an unexpected flare‑up of hostility between the neighboring countries Galette and Biscotti, as well as taming a malicious demon. It is no surprise that the boy made many friends and even more girlfriends. To his dearest of them, Princess Melchiore Filiano Biscotti, Sinku promised to return—and heroes always keep their word! Company is more fun abroad, so a whole delegation heads to Froniard for the summer holidays. Sinku invited his childhood friend Beki and cousin Nanami—an old rival and equally determined athlete—to join him. Now Biscotti and Galette have their own heroes, and the modest Beki we believe will not stay on the sidelines. Thus, troops are gathering, sacred weapons await, and new warriors, knights, and crowned individuals rush onto the stage. The days of Sirius"s "dog star," the hottest summer days in the world of the series, are still ahead!