Azula, a sickly girl who feels isolated and unloved by her family, except for her younger brother Arrio. One day, she meets Arch, a handsome and mysterious guardian angel who has been protecting her since childhood. Azula can see Arch, which is unusual, and he reveals himself to her. Arch has developed strong feelings for Azula and wants to heal her, but his powers are limited, and he must seek permission from a higher authority, Alpha.