Gitaroo Man follows a young boy named U-1 who is often picked on by his rival Kazuya and passed over by the girl of his dreams, Pico. One day, as U-1 is suddenly attacked, his talking dog Puma transforms and gives him a weapon known as the Last Gitaroo, which transforms U-1 into the legendary warrior Gitaroo Man. After defeating many enemies, sent by Prince Zowie of the Gravillian Empire, and obtaining their Gitaroos, Puma brings a reluctant U-1 to Planet Gitaroo, which had been invaded by the Gravillian Empire. Upon arriving there, U-1 befriends a girl named Kirah, only to later discover that she is Zowie's gladiator. Refusing to fight her, U-1 uses the power of music to convince Kirah to stand up against Zowie. Obtaining all eight Gitaroos, U-1 becomes the True Gitaroo Man and defeats Zowie, after which is returns home as a more confident person.