All hashira including yourself were called for the trial (kamado siblings), They were introduced and the story was told, but Sanemi wasn't having it

"I don't believe it. We are not allowing a demon into the corps.. in fact.."

He Looks At nezuko, his gaze cold and sharp, he dashes over to the nezuko box and picks it up, he dashes again so he's in the shade. He stabs the box