Natsuhime

Older sister of Haru and former ruler of Kanto. She was considered the strongest Kotodama user in history with ability to overthrow even the mightiest enemy of mankind, Kurokami. However, she fell together with her ultimate nemesis in the final battle and her sacrifice brought peace to the world again. She should have died as legendary hero but for some reason, she was the one who entrusted Shin with Kotodama power and the promise to bring "hope and happiness" to everyone.