Discarded in a rubbish bin, Colonel is a clockwork tin soldier doll possessing an authoritative demeanor despite his small size and artificial nature. His military personality surfaces when he commands amusement park security guards to activate the lights during a nighttime visit.

After meeting the homeless boy Ricky (Ted in the original Japanese version) and the talking stray dog Mack (Pudge in English), Colonel accompanies them to the amusement park. Pursued by guards, he joins their escape using fireworks rockets that propel the trio into the countryside. There, they encounter the elderly explorer Lemuel Gulliver.

Colonel boards a rocket ship bound for the Planet of Blue Hope alongside Gulliver, Ricky, Mack, and Gulliver's crow assistant. Throughout the space voyage, he maintains his toy soldier identity without complex development or personal history beyond his origin as a discarded object, consistently interacting with a straightforward, militaristic bearing.

On the Planet of Blue Hope, Colonel witnesses the conflict between the planet's inhabitants and hostile robots from the neighboring Purple Planet. He participates in the group's efforts to overthrow the robot regime, though specific actions in the climactic battle remain undocumented.

Following the successful liberation of the Planet of Blue Hope, the adventure ends with Ricky awakening back on Earth. Colonel lies inanimate and silent in the rubbish bin where he was first discovered, suggesting his animated existence occurred solely within the context of Ricky's dream-like experience.