Free-spirited and hates anything dishonest. He is a bit impatient but possesses a kindness that prevents him from ignoring anyone 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 always keeps his promises, never betrays others, and stands firm in his own sense of justice. Usually lighthearted and playful, remaining calm in any crisis, he surprises onlookers with a level of intensity and sharpness in critical moments that makes him seem like a different person. In short, he is the world's fastest hedgehog who cannot stay still for even a single moment.

A kind-hearted fox with two tails. He can fly through the sky by rotating his tails like a propeller. Inspired by watching Sonic run, he came to admire him and started following him wherever he went. He loves tinkering with machinery as much as Dr. Eggman and develops various gadgets to assist Sonic's activities.

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 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 sparring partner. 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 often easily tricked. He is a treasure hunter and a martial arts expert. Possessing incredible physical strength, he can shatter rocks with his punches. He also excels at gliding and climbing walls.

A girl deeply in love who follows Sonic everywhere, today and tomorrow, whenever she sets her mind to it. She calls herself Sonic's girlfriend. A bright and 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 feelings and momentum.

Shadow the Hedgehog, 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 techniques like Chaos Control, which warps time and space. He possesses an extremely straightforward mind that will stop at nothing to achieve his goals. He is usually prickly and blunt.

His full name is Silver the Hedgehog. A silver hedgehog from the future who wields psychokinetic powers. He has a strong sense of justice and an honest, warm personality that never loses hope even in desperate situations. He strives 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 his devastated timeline. 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 the others.

Her full name is Blaze the Cat, but everyone calls her Blaze. She is the princess of her world, entrusted with the mission of guarding and wielding the Sol Emeralds. She usually maintains a calm and dignified demeanor. However, this seems to be because she tries to suppress her inner passion with logic. While faithful to her duty as a guardian, she tends to bind herself too strictly to her responsibilities. Perhaps because of this, she is quite shy in large groups. However, her mindset seems to have changed a bit after 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 leaps through time and space while doing so. She is currently living in the house.