Mikasa is Eren's childhood friend, along with Armin. Mikasa shares an unbreakable bond with Eren following events in their past, and rushes to protect him whenever he is in danger. Mikasa possesses impressive fighting skill and strength even as a child. As a teen, Mikasa is considered a genius among all the army trainees and is incredibly skilled at combat and agility. She constantly worries for Eren's well-being and lives to protect him.

Hachiman is the story's main protagonist, an isolated, friendless boy who is pragmatic to a fault. His most prominent feature is his set of "dead fish-eyes." He firmly believes that "youth" is simply an illusion created by hypocrites, for hypocrites, born from the ashes of past failures. In this state of apparent corruption, he is coerced into joining the Service Club by his futures advisor in the hopes that exposing him to the world will change his personality, and ultimately make him a "better person." He is called "Hikki" affectionately by Yui. (Source: Vistrans, Yahari Wikia)