Free-spirited and hates dishonesty. He is a bit impatient but possesses a kindness that prevents him from ignoring someone in trouble. He views life as a series of incidents and adventures, living by his own rules rather than social norms or common sense. He keeps his promises, never betrays others, and stands firm in his sense of justice. Usually lighthearted, playful, and detached even in a crisis, he surprises onlookers with a radical sharpness in critical moments as if he were a different person. Regardless, he is the fastest hedgehog in the world, unable to stay still for even a single moment.

A warm-hearted fox with two tails. He can fly through the air by rotating his tails. He gained courage after seeing Sonic run and began following Sonic, whom he admires, wherever he goes. He loves tinkering with machines as much as Dr. Eggman and assists Sonic's activities by developing various inventions.

A cheerful and powerful echidna. He lives alone on Angel Island, a floating island in the sky, guarding a massive gem called the Master Emerald for reasons unknown to him. This is the fate of the Knuckles clan, and he is currently the only being capable of controlling the Master Emerald. He is Sonic's rival and fighting companion. If Sonic is the 'wind,' he is the 'mountain' destined to stay in one place. Due to his single-minded and stubborn nature, he is easily deceived. He is a treasure hunter and a martial arts master. With immense punching power, he can shatter rocks. He also excels at gliding and wall-climbing.

A girl deeply in love who follows Sonic everywhere, today and tomorrow, once she sets her mind to it. The self-proclaimed girlfriend of Sonic. She is a bright, energetic mood-maker who hates losing and possesses great initiative. In crucial moments, she pulls out her favorite Piko Piko Hammer from nowhere, showing prowess that rivals the boys. Even Sonic is overwhelmed by her unwavering heart and momentum.

A black hedgehog resembling Sonic, Shadow the Hedgehog. His true identity is the Ultimate Lifeform created by Professor Gerald Robotnik, Dr. Eggman's grandfather. He not only looks like Sonic but also possesses similar abilities. He specializes in techniques like Chaos Control, which warps time and space. He has an extremely straightforward mind, stopping at nothing to achieve his goals. He is usually prickly.

His full name is Silver the Hedgehog. A silver hedgehog from the future who wields psychic powers. He has a strong sense of justice and a sincere, warm personality that never loses hope even in desperate situations. He seeks to protect world peace and people's smiles, even at the cost of self-sacrifice. He came from the future with the goal of defeating the "Iblis Trigger" to change a devastated future. He can use psychokinesis, a superpower that allows him to control the movement of objects. He fights to restore peace using techniques that bind objects or paralyze enemies. Currently, he is living together with Sonic and his friends.