As punishment for consummating his marriage to a human, the celestial Hotsuka is expelled from heaven and his powers reduced. Human, and imprisoned, Hotsuka is freed by a djinni, Tenshi, who tells him his newborn son will die if he doesn't receive a dragon pearl.
No sooner has he found his son, Hotsuka walks into a trap. Injured, he is taken in by monks who, as payment for his treatment, require five years of service in a monastery no monk has ever escaped. Over the next two decades, Hotsuka discovers his humanity while rising through the ranks to become abbot.
Then, one day, Tenshi arrives with terrible news. Will Hotsuka leave the monastery and embark on a perilous adventure that will change his life, the world he calls home and the universe?