Born from a rock on a mountain, a nameless and solitary monkey's life changes when he meets RinRin, a fellow simian who becomes his first friend. Through her support, he rises to become king, but power taints his nature. Determined to surpass human intelligence after RinRin's comment, he departs to train with a wise hermit, earning the moniker Son-Goku. However, his arrogance leads to trouble when he steals a precious fruit from heaven and is later rescued by a monk, striking a deal to join a perilous expedition to India, setting the stage for his next arduous trial.