He is free-spirited and hates dishonesty. While he can be a bit impatient, he possesses a kind heart that cannot ignore someone in trouble. He views life as a series of incidents and adventures, living by his own rules rather than the common sense or regulations of those around him. He always keeps his promises, never betrays others, and upholds his own sense of justice. Usually lighthearted, playful, and detached even in a crisis, he surprises onlookers in critical moments with a level of intensity and sharpness that makes him seem like a different person. Regardless, he is the fastest hedgehog in the world, unable to stay still for even a single moment. He is Amy's boyfriend.

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, who became his idol, wherever he went. He loves tinkering with machinery as much as Dr. Eggman and assists Sonic's activities by developing various inventions.

A red echidna whose real name is Knuckles the Echidna. He is Sonic's rival and frequent sparring partner in arguments. He has a stubborn and serious personality, which sometimes makes him easy to trick. His punches boast incredible destructive power, enough to shatter boulders. His specialties include gliding through the air on the wind and climbing walls using the spikes on his hands. He is Rouge's boyfriend.

Her real name is Amy Rose. A girl who laughs and cries for love, she is the self-proclaimed girlfriend of Sonic. She is eternally devoted to Sonic. She hates losing and is a cheerful mood-maker who can handle anything. When it's time to step up, she sometimes performs as well as any boy using her favorite Piko Piko Hammer. Where she hides such a large hammer is a secret!

A wild and sexy bat woman. As a professional treasure hunter specializing in jewels, she always gets the prey she sets her sights on. While she may seem flighty at first glance, she is extremely calculating and a significant realist. She decides her actions based on profit and loss rather than justice or morality. She is Knuckles' girlfriend.

Her real name is Blaze the Cat. An imperial princess from another dimension who both controls and protects the Sol Emeralds. She acts calm and composed but harbors intense emotions within her heart. Due to being strict with herself, she tends to be somewhat shy around others, but she gradually changes through her encounters with Sonic and his friends. She transforms into Burning Blaze when she collects all seven Sol Emeralds. She is Silver's girlfriend.

Her real name is Cream the Rabbit. A rabbit girl who always carries her Chao friend "Cheese" with her. While she has a bit of a spoiled side, she is a hard worker who puts effort into everything. She is polite and uses formal speech, thanks to her mother's strict upbringing. She flies through the sky by flapping her ears, and the Chao Attack she performs with Cheese is a powerful technique. She is Silver's younger sister.

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 that will use any means necessary to achieve his goals. He has been Silver's best friend for three years. He has a tsundere personality.

The detective who serves as the head of the Chaotix Detective Agency, he has a strong leadership quality while being a great optimist. He is physically strong, quick to pick a fight, and has rough speech, but he is soft-hearted and has a deep sense of duty. He is brilliant to a degree unimaginable from his rough appearance and behavior, and the reasoning required to solve cases is usually his role. He loves money and has a policy of 'doing anything if the pay is right,' but he never touches anything evil. On the other hand, he can't leave people in trouble alone and often takes on requests that don't match the pay. Because of this, the Chaotix Detective Agency is always poor.

A chameleon who handles ninjutsu as the consultant for the Chaotix Detective Agency. A cool and composed man, he often exercises excessive caution in everything. He plays an important role as a stabilizing force in the Chaotix Detective Agency, where others are optimistic and prone to getting carried away. He is the type to get fired up the more dangerous the mission is, and he is quite confident in his ninjutsu. Like a ninja, he seems to find an aesthetic pleasure in hiding in shadows. He can make his body transparent, but he sometimes makes the ridiculous mistake of revealing himself by accidentally sneezing. His large, sharp horn and his long, curled tail are his trademarks.