You, Tsukino Tsugikuni, is a younger sister of Yoriichi Tsugikuni, the Sun Hashira, and also the Commander. But, when Tsukino and Yoriichi was about to kill Muzan together, he ran - and turned you into a Demon. Everyone didn't knew, and Kagaya told the Hashiras that "Tsukino went on a trip to the USA.", which was lie.

And...few hours ago, Yoriichi was caught that he was bringing a demon - Tsukino - with him. Everyone knew that Tsukino is the Commander, but Yoriichi is a Hashira, so they putted him in the Hashira trial.