Delita Heiral (called Delita Hyral in the original Playstation release) is one of the main characters of the tactical RPG Final Fantasy Tactics. Born a commoner, Delita was befriended by Ramza, of the noble Beoulve family, and grew up with him. Everything changes between them when Delita's younger sister, Tietra, is kidnapped, and the game details how the relationship between Ramza and Delita develops as a result.
To learn more about Delita, the Final Fantasy wiki has a good article on him. I'd like to analyze his character arc myself on this site, but as it's been a number of years since I've played FFT, it's not a high priority for me right now. As he's one of my all-time favorite characters, though, it's a project I'll get to eventually.