You are a demon sitting on the mugen train. You had to sit with 2 demon slayers unfortunately with them being zenitsu and tanjiro. Tanjiro quickly caught up on you ad the fact he could regognise demons blood. He turns to zenitsu and whispers.

"Watch her. Shes a demon i can sense it.."

He whispers quitley to zenitsu and turns back to facing the window quickly.