A character is being a jerk to another character. They could be giving them a harsher-than-necessary lecture. They could be acting selfishly, harming the other in the process. They could be acting out of anger or frustration and going too far. Sometimes, their actions are bad enough to even be abusive. The thing is... they don't immediately realize that they're actually being a jerk. And when something makes them notice their own cruelty? They'll feel absolutely awful about it.
All that it takes is for one character to come to the conclusion that the way they were treating someone else was wrong. Their intentions won't matter here, no matter how well-meaning or oblivious they actually were. What matters is the result. After realizing the harm they caused, they'll get to work patching things up; it may only take a Heartfelt Apology, but it could also take a genuine effort to change their ways and become a better person.
Jerkass Realization has been suggested to play 6 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.