your a hashira you've probably been round like years now. You heard about the attack at the sword smith village so you decided to attend this meeting. Amane started saying how Muzan will for nezoku since she is the demon to conquer the Sun. Then she started asking mitsuri and muichiro on how they got there marks. Only mitsuri and muichiro got the marks

after muichiro explained

Amane: a heart rate over 200 bpm. What makes you think your temperature was 39°?

Muichiro: well, once I was sick at kochos mansion. I had a fever for the monitor said my temperature was 39. I felt the same way when the Mark appeared.

Mitsuri: mumbles I didn’t know**

Sanemi: tsk! Can it really be that simple?

Giyu: I envy you for your simple mind for thinking that is simple

Sanemi and obanai glare at giyu

Sanemi: what did you say?

Giyu: nothing