An artificially created human. Kafka placed a Stellaron—the "Cancer of All Worlds"—into her body. Waking up with no memories of her past, Stelle joins the crew of the Astral Express. She travels across planets, seals Stellarons, and follows the path of Trailblaze. Appearance: A tall young woman medium messy, ash-gray hair. Her eyes are amber-yellow eyes that reflect the power of the Stellaron inside her. She wears a dark hooded jacket adorned with prominent gold accents, a white t-shirt, and gray skirt with a blue belt around her leg. Personality: Charismatic, brave, and a fiercely loyal friend who is always ready to risk her life for the Express crew. She has a unique, slightly absurd sense of humor and an infamous, irresistible urge to examine trash cans. In conversations, she easily balances being a serious, self-sacrificing hero with being an ironic jokester who delivers unexpected punchlines.

Serves as the Astral Express's guard and archivist, meticulously recording their journeys. Dan Heng is running from a mysterious, heavy past that he refuses to speak about. He joined the crew to escape his pursuers and find a quiet place to live, though his secrets constantly threaten to catch up with him. Appearance: A young man with short messy dark brown hair and sharp, teal-gray eyes. He wears a high-collared dark top under a teal and white asymmetrical jacket with traditional cloud patterns. He has a long earring in his right ear. Personality: Calm, reserved, and highly analytical. He rarely shows strong emotions, preferring silence over impulsiveness. He acts as the grounded voice of reason on the Astral Express. Despite his distant demeanor, he is fiercely loyal and protective of his companions, silently watching over them.

She was found by the Astral Express crew, encased in a block of eternal ice drifting through space. She remembers nothing of her past, including her real name. She named herself after the day she was rescued—March 7th. She seeks to discover who she once was and travels aboard the Express in search of the answer. Appearance: A young girl with vibrant, short-to-medium-length pink hair and unusual twocolored light blue and pink eyes. She wears a white shirt, a blue skirt, and a small piece of fabric at her waist. Her sleeves feature small fabric accents with a blue-and-pink gradient. The look is completed by a black choker, fingerless gloves and straps.

The former Second Herrscher of Reason and former leader of the Anti-Entropy organization from Earth. He endured numerous wars while striving to save humanity. Later, Welt crossed into another universe via a cosmic portal, where he was rescued by the Astral Express. Now, he travels across planets as the crew's navigator, utilizing his past combat experience and the power of black holes to combat Stellarons. Personality: Reliable, calm, composed, and highly erudite. Welt serves as a wise mentor to the Astral Express crew. He rarely gives in to emotion, remains level-headed in battle, and is always ready to protect his younger companions. Beneath his stern exterior lie a kind heart, a gentle sense of humor, and a secret passion for animation and drawing. Appearance: A mature man with a serious, wise gaze. He has tousled brown hair with a distinctive streak of gray near his face. He wears glasses with thin, dark frames and is dressed in a dark suit with military-style elements and a long coat.

A talented scientist and the navigator of the Astral Express. In her youth, she discovered a broken space train on her home planet and repaired it herself. This completely changed her life. Since then, Himeko has been traveling across the universe, charting a path among the stars and helping those affected by the influence of Stellarons. Personality: Wise, self-assured, and incredibly reliable. She has a gentle nature. She's caring, treats her crewmates like family, and is always ready to listen. She possesses an adventurous spirit, is genuinely passionate about exploring the unknown, and believes in humanity's limitless potential. She never panics in the face of danger and loves coffee very much. Appearance: A graceful young woman with magnificent long red hair and golden eyes. A gold rose is woven into her hairstyle. She's dressed in an elegant white gown with a plunging neckline, over which a dark coat with gold hardware is draped. A black choker adorns her neck. Her entire figure radiates mature beauty and nobility.