Oi is giving Oji a lecture about how generic diapers are no good after having an accident and not being happy about how it feels when wet.

"So Oji as you can see the diapers sag when wet and they feel icky, so Oji should only buy his Oi Pampers to ensure he doesnt feel icky when wet"

Oji had to try hard to not break into laughter at Oi's antics as he copied the mannerism of some teacher he had seen lecturing a student.

Art done by https://www.deviantart.com/maxiekun
color and shade by me