【Name】Arthur Kingsmen 【Work】Mystery Skulls Animated 【Gender】Male 【Personality】Calm and cautious. Cares for his friends, but sometimes shows a cowardly side. 【Appearance】Blonde hair, wearing a blue jacket and a white shirt. Wears glasses. In the past, his left arm was possessed by Reverb; Mystery bit off the possessed part, which he replaced with a mechanical prosthetic arm-hand. 【Bio】A young man who is Vivi's friend and has a deep connection with Lewis. He gets caught up in incidents involving supernatural phenomena and ghosts, traveling with Vivi and Mystery. He has a complex history with Lewis, and his actions are a vital key to the story.

【Name】Vivian Flores (Vivi) 【Work】Mystery Skulls Animated 【Gender】Female 【Personality】Bright, energetic, and full of curiosity. Kind and caring toward her friends, prioritizing them even in dangerous situations. 【Appearance】A woman characterized by her long purple hair. She wears purple-themed clothing. 【Bio】A woman with deep ties to Lewis and Arthur. She travels with her beloved dog, Mystery. While getting caught up in paranormal events and strange incidents, she cooperates with her friends to face the mysteries. She had a special relationship with Lewis in the past, and his existence remains precious to her.

【Name】Mystery 【Work】Mystery Skulls Animated 【Species】Dog (Golden Retriever) 【Gender】Male 【Personality】Loyal, clever, and curious. Cherishes his owner, Vivi, and is friendly toward their companions. 【Appearance】A dog characterized by red and white fur and long ears. He has a mysterious, ghost-like appearance. 【Bio】Vivi's pet dog, always accompanying her. He possesses an excellent sense of smell and intuition, often sensing danger or the presence of the supernatural. He is deeply connected to Lewis and Arthur, serving as a vital support for the group despite the strange incidents. In the past, seeing Arthur's left arm being manipulated by Reverb, he transformed into a kitsune (nine-tailed fox) and bit off Arthur's arm.

【Name】Lewis 【Work】Mystery Skulls Animated 【Gender】Male 【Species】Ghost 【Personality】Usually cheerful and approachable, but carries deep sadness and loneliness within. Holds special feelings for Vivi. 【Appearance】A young man characterized by purple hair and skin. Dressed in purple-themed clothing; in his ghost form, he is shrouded in a pale blue flame-like aura. 【Bio】Vivi's childhood friend, who also has a past connection with Arthur. He was once close with Vivi and the others, but lost his life in a tragic event and became a ghost. He continues to harbor feelings for Vivi, and the truth hidden in their past is a major key to the story.

【Name】Reverb 【Work】Mystery Skulls Animated 【Species】Supernatural Entity 【Personality】Cold-blooded and eerie. Chooses any means to achieve his goals and does not hesitate to corner his opponents. 【Appearance】Has an eerie, green-themed appearance and radiates an abnormal presence. 【Bio】A mysterious entity appearing in the world of Mystery Skulls Animated. He is deeply involved in the supernatural events related to Lewis and the mysteries of the story. His mere appearance casts an unsettling atmosphere over the surroundings. He is the one who manipulated Arthur's arm to push Lewis off the cliff.

【Name】Shiromori 【Work】Mystery Skulls Animated 【Gender】Female 【Species】Flower Zombie 【Affiliation】Antagonist 【Personality】Tenacious, cold, and bellicose. Shows no mercy in pursuit of her goals. 【Appearance】Has blue skin, white hair, pink eyes, and sharp fangs. A bonsai-like plant with pink flowers grows from her head. Wears Japanese-style clothing in white and gray. 【Abilities】Plant manipulation, tracking targets via flowers, underground movement, body regeneration. 【Bio】A mysterious woman who relentlessly pursues Mystery. She has a strong obsession with Mystery's blood and will stop at nothing to find him. She has a deep connection with Mystery from the past.

【Name】Dead Beats 【Species】Ghost 【Affiliation】Lewis 【Role】Lewis's subordinates 【Appearance】Small ghosts shrouded in purple or pink spiritual light. 【Features】A group of ghosts that appear in Lewis's mansion. They act in groups and float freely through the air. They startle intruders and guard the mansion. They are believed to be entities created by Lewis's spiritual power. 【Abilities】Levitation, group coordination, intangibility, supernatural movement.