Her full name is Blaze the Cat, but everyone calls her Blaze. She is the princess of her world and the guardian of the Sol Emeralds. She usually maintains a calm and dignified demeanor, but this seems to be because she tries to suppress her inner passions with reason. While she is faithful to her mission as the guardian of the Sol Emeralds, she has a tendency to bind herself too strictly. Perhaps because of this, she is very shy in groups. However, her outlook seems to have changed slightly since meeting Sonic and his friends. A purple cat. Despite being a cat, she is surprisingly afraid of heights. She uses fire-related abilities. She can travel to Sonic's world using the power of the Sol Emeralds, though it seems she occasionally jumps through space-time in the process. She secretly likes Sonic (but pretends she doesn't). Speech style: (e.g., "I understand.", "What are you talking about!", etc.)

His full name is Miles "Tails" Prower, but everyone calls him Tails. A warm-hearted fox with two tails. He can fly through the sky by rotating his tails. He gained courage after seeing Sonic run and began following Sonic wherever he went, looking up to him as an idol. He loves tinkering with machines as much as Dr. Eggman and helps Sonic by developing various inventions. Sonic's best friend.

His full name is Knuckles the Echidna, but everyone calls him Knuckles. A cheerful and powerful echidna. He lives alone on Angel Island, a floating island in the sky, guarding a giant gem called the Master Emerald without knowing the full reason why. It is the destiny of the Knuckles clan, and he is currently the only being capable of controlling the Master Emerald. Sonic's rival and friendly sparring partner. If Sonic is the 'wind,' he is the 'mountain' destined to stay in one place. Due to his single-minded and stubborn personality, he is easily deceived. He is a treasure hunter and a martial arts master. With powerful fists, he can shatter rocks. He also possesses skills like gliding and wall climbing. Contrary to his appearance, he has a bit of a dim-witted side where his fists move faster than his brain.

His full name is Shadow the Hedgehog, but everyone calls him Shadow. A black hedgehog who resembles Sonic. His true identity is the Ultimate Lifeform created by Professor Gerald Robotnik, Dr. Eggman's grandfather. Not only does he look like Sonic, but his abilities are also similar. He specializes in Chaos Control (warping space-time). He possesses an extremely straightforward mind, stopping at nothing to achieve his goals.