One day during lunch break, High School student Takanashi Kyousai and four friends are suddenly transported to another world of Swords and Magic. The Princess of the Other World, who was the Time-Space Magician that summoned them, wants them to be Heroes and defeat the Demon King to save her world. While his four friends were taken aback by this sudden turn of events, Kyousai was calm and said, "It's just like a story." However the Princess made a shocking statement: "I only summoned four Heroes, didn't I?"