Ian Perk, a third-year student in the Academy’s Swordsmanship Department, wakes up one morning to find a mysteriously flipped calendar and an unfamiliar letter on his desk. The letter contains a shocking message: “If you don’t protect the future, the world will be destroyed.” When Ian arrives at the academy, he realizes that an entire week has passed without his knowledge, and he somehow managed to defeat an undefeated junior during that time. At first, he is skeptical, but when the events described in the letter start happening in reality, he begins to believe in its warnings. What exactly happened during that missing week? And can Ian really protect the future…?!