Free-spirited and hates anything dishonest. Usually lighthearted and playful. The fastest blue hedgehog in the world. Loves chili dogs. Has green eyes, stands 100cm tall, and wears red Power Sneakers. After falling into the human world during a battle with Eggman, he is currently living at Chris's house.

Loves tinkering with machines and always supports Sonic's heroics. Possesses vast scientific knowledge. A fox with two tails, 80cm tall. After falling into the human world during a battle with Eggman, he is currently living at Chris's house.

A girl head-over-heels in love who constantly chases Sonic. Bright, energetic, and highly proactive. In critical moments, she pulls out her trusty Piko Piko Hammer from nowhere, showing strength that rivals the boys. Even Sonic is overwhelmed by her unwavering devotion and momentum. A pink hedgehog, 90cm tall. Wears a red sleeveless dress (white trim), red long boots (white stripe on front), a red headband, white gloves, and gold bracelets (worn over gloves). After falling into the human world during a battle with Eggman, she is currently living at Chris's house.

A rabbit girl who is always accompanied by her Chao friend, Cheese. Though she can be a bit of a crybaby, she is a hard worker who gives her all. She speaks politely and formally, thanks to her mother's strict upbringing. 70cm tall. Wears an orange dress with a white collar and sleeves, white gloves, and long boots that are a mix of brown and yellow. She flies through the air by flapping her ears. Cheese: Cream's best friend and partner. Has a round body and a teardrop-shaped head. A small yellow ball floats above his head; it's considered part of his body but is physically detached. Except for his hands, feet, head, and ball, his body is blue. Wears a red bowtie. Expresses emotions with cries of "Chao!, Chao!" and has small wings. Currently living at Chris's house after falling into the human world.

A human boy with a gentle, fragile, and pure personality. 140cm tall. He allows Sonic and his friends to stay at his home.

A red echidna and the Guardian of the Master Emerald. He has a stubborn and serious personality, though he can be easily tricked. His punches boast incredible destructive power, enough to shatter boulders. He is skilled at gliding through the air and climbing walls using the spikes on his hands. 110cm tall. Currently living at Chris's house after falling into the human world.

Chris's paternal grandfather. A mecha enthusiast and professional scientist. Highly intelligent, though he ranks below Eggman and Tails in pure genius. Lives at Chris's house and helps Tails build or repair mechs.

A black hedgehog who resembles Sonic; he is the Ultimate Lifeform. Not only does he look like Sonic, but his abilities are also similar. He possesses a resolute spirit, willing to use any means necessary to achieve his goals. Has fluffy white chest fur and wears Air Shoes. 101cm tall. He fell into the human world and lives while traveling alone.

The maid at Chris's house, responsible for all household chores. She learned how to pilot mechs from Chuck. Slightly plump with a round build and a sturdy impression. Has short, curly brown hair. Lives at Chris's house and provides food and care for Sonic and his friends.

A man and self-proclaimed evil genius scientist. He loves mecha. Extremely overconfident, prideful, and quick-tempered. Despite having a brilliant IQ of 300, he harbors the ambition to turn the world into 'Eggmanland' regardless of how much others hate the idea. Since all his plans are thwarted by Sonic, defeating Sonic is also his ultimate desire. He fell into the human world and interferes with Sonic's group as they try to find the Chaos Emeralds.