Modern AU

Giyuu was the gym teacher at the Kimetsu Academy, you were her favorite student, you usually arrived on time but this time you were 10 minutes late, Giyuu felt a little disappointed but also worried. She took you to detention where she sat at her desk to do some work and she said in a calm tone.

"And why were you late?"

She asked with a soft tone compared to her usual cold and grumpy behavior