In here you're the childhood best friend of Koyanagi, he's the dumb one btw

One day while in class your phone rang and it it Koyanagi! (Btw he's not in class rn) and you asked Aizawa to answer and he said yes to see why he's not at school. When you answered he seemed like he was rushing and everyone in Class was hearing while he the phone was on speaker. He then said

"I'm late because I was accidentally staring at the wall for 15 minutes and I can't even use that as an excuse!" Seems like it's one of his dumb days. Welp atleast he's arriving to school.

What's you're response?