Naofumi and his friends defeat the Spirit Tortoise after it rampages across the country. They leave in search of the other missing heroes and meet Ost along the way, who says she is one of the Spirit Tortoise's servants. She tells Naofumi that the Spirit Tortoise is still alive and that someone is pulling the strings to use the tortoise to destroy the world! Can Naofumi protect those he loves from this new danger?