Kirito is a mean nerd. He pretend to be nice, but actually he's mean.
Kirito is mean and insane. He mocks everyone and see himself as genius. Only few people likes him.
People who got bullied by him
Kirito likes bullying everyone.
Kirito has many enemies. His has an archenemy named Hyde, who's from Under-Night-in-Birth. Hyde always defeats Kirito and kidnaps Asuna. He and other people in Under Night in Birth even beat other people in Dengeki Bunko, Kirito's home company.(ps. Hyde also hates the King) However, Kirito made some friend in Shonen Jump. Hyde is always defeated by them.
If you don't know why they're archenemies, just search Kirito vs Hyde.