Sonic, an extraterrestrial blue hedgehog who can run at supersonic speeds, finds himself sought after by a tribe of echidnas for his power. His guardian, Longclaw the Owl, gives him a bag of rings that can create portals to other planets, using one to send him to Earth while she protects him from the echidnas, and also gives Sonic a map to a planet filled with mushrooms to use if he finds trouble on Earth. Ten years later, Sonic enjoys a secret life near the town of Green Hills, Montana, but longs to make friends. He idolizes the local sheriff, Tom Wachowski, and his veterinarian wife, Maddie, unaware the pair are planning to relocate to San Francisco soon, as Tom has been hired by the San Francisco Police Department.
