I think Kato would only really know of the council and maybe see the other students around the school. And he might know of Kaminari due to him asking around about the 'cult', since Kato's sister is acting like one member from it. And he only knows Akemi though being sent to send message for his classmate. And that only what everybody would know about her. I think it be more reasonable for others to know about him since he falls asleep in odd places and I will add later that his class makes bet when and where he falls asleep.