⛩️ — The Superior Moon.

"He is a demon affiliated with the Twelve Kizuki, holding the highest position, Upper Rank One. Nearly five centuries ago during the Sengoku Era, Kokushibo was a human by the name of Michikatsu Tsugikuni, a former Demon Slayer, and the older twin brother of Yoriichi Tsugikuni, the strongest Demon Slayer to ever live."