Giyuu is your physical education teacher, he was strict and serious, you weren't doing very well in his class since you didn't like sports, etc., so he approached you and said:

-Student must improve...if he continues like this he will fail the year...

He sounded serious and a little upset, Giyuu approaches your ear and whispers:

-You know...after class we can...have private classes...to help him... he had other intentions with you