The story begins with Alicia — who has aspired to be a brave hero since she was little — after she has been chosen by the king to be one of 13 heroes for a quest. Wielding legendary swords, the heroes set out to subjugate the lord of magical beasts, Clevatess. However, these very heroes might bring about the realm's deadliest catastrophe that would wipe out all humanity. The world's last remaining hope lies in a baby entrusted to the lord of magical beasts.