220 years ago, in the legendary Dragon Demon War, Hero Azell ended the war by killing the evil Dragon Demon race's King Atein. He was able to save the population, but as a consequence, he was cursed. While he was dying, the high magician suggested a gamble that might save his life.

'The Dragon's hibernation is the only key to saving your life.'

Instead of a human's sleep, he slept the sleep of the dragons and he was able to overcome the curse. Now he is realizing that he has slept way longer than a human's life span.