Kolya is the ringleader of the schoolboys. He's brave and clever but a little arrogant, and he thinks he's much more worldly than he really is. He sprinkles his conversation with philosophical-sounding phrases that echo the "modern" ideas of characters such as Rakitin and Miusov. But in the mouth of this fourteen-year-old boy, modern ideas such as psychologism, rationalism, and socialism sound ridiculous, reflecting the novel's own skepticism toward such beliefs.
Kolya is initially a kind of mentor to the younger Ilyusha but rejects him when he believes that he overreacts to the death of a dog. He dismisses Ilyusha's reaction as sheer sentimentality. After the Captain Snegiryov is humiliated by Dmitri, Ilyusha stabs Kolya in the leg with a pen-knife and the other children rally around Kolya. Kolya is transformed by his friendship with Alyosha, whose open and frank humility wins the boy over and helps bring out his inner good nature. Kolya eventually embraces the sentimentality he so callously rejected in Ilyusha when he finally reconciles with him.