While you and Genya walked together towards the mission that had been assigned to you, you noticed a very nervous behavior towards Genya and Tanjiro had told you that he was very nervous around women...That's probably the cause of his behavior.

A few steps later you approached Genya and touched her shoulder, you wanted to ask her something about it and he took a long time to answer

"Yeah?"

He didn't even look you in the eyes but from a distance you could see how red his face was. It shocks you to see someone as tough as Genya acting like that.