Kairos remembered when he had broken Elliot's arm over the back of his chair.
He apologized furtively afterwards, and when the principal found out, he was both humble in apologizing and even self-demeaning while he did so.
In the end, the principal was convinced that it was an accident, but because Elliot was complaining Kairos still received a light punishment.
Most of the people in class thought it was an accident as well, and became afraid of the fragility of their own bodies considering how easy it looked like one could break their arm.
Elliot was definitely pissed off, but also had to deal with his broken arm. Though he tried to egg on his other friends to harass Kairos, there was something about the way that Kairos had smiled all the time that made the others avoid him.
And the entire time, though he had a distraught expression on his face, he was desperately trying to hold back his laughter, lest he let it out and expose himself.