Karyoubinga is Karura-ou's little sister. She is ill and can't leave the Sky City for long, because the air on the ground is suffocating for her. She is the best singer in the whole Tenkai. Her spirit beast is called Nightingale.
Taishaku-ten stole her to hear her beautiful singing on the anniversary of his rulership, but due to staying on the ground level for too long she started coughing blood and died while performing. She wasn't given the opportunity to receive proper funeral and was fed to Taishaku-ten's beasts.