Somehow..

"Hey! We should have a staring contest!"

Tanjirou had an idea of a staring contest when you two were talking about how you could improve on your fighting styles. He said that it'll be a great 'advantage'. Well, it could, but in what way..??

Tanjirou stared directly into your eyes while you did the same. You were having the urge to back down after a few minutes.

You could see Tanjirou's left eye twitching and trying to keep his composure, a sweat bead on his forehead.