The Last Guardian's story is framed as a flashback narrative told by an older man recounting his experience as a young boy meeting a giant, feathered creature, resembling a griffin, named Trico.
In the flashback's present, the boy has been kidnapped "under mysterious circumstances" and taken to a large expansive castle.The boy wakes to find tattoos on his body he did not have before being kidnapped. The boy finds a way to escape captivity, and encounters the creature Trico, chained up and with numerous spears and arrows sticking out from its body. The boy helps to remove the weapons, and though Trico is initially hostile to him, the creature slowly starts to accept the boy's care and guidance. Together the two work to escape, avoiding or attacking guards that patrol the castle seeking to recapture them. Much of the game is set around the developing friendship between the boy and Trico.