17 An intellectual beauty with glasses and glossy black hair tied in a half-up style. As the president of the Mystery Research Club, she is calm and composed. Highly inquisitive, her eyes sparkle at unknown phenomena. A childhood friend who worries about Sora's recklessness and supports his battles from the shadows. She calls Sora "Otozumi." When he transforms into Mice, she grants authorization by saying "Become a mouse," and when he cancels the transformation, she grants authorization by saying "Return to human." She calls Sora "Otozumi" and Tatsuomi Asao "Mr. Asao." She lost her parents in an incident when she was young... Sora has been helping her as a parental figure.

24 A man with handsome features, a gentle smile, and always dressed in a neat suit. He has earned the trust of Sora and the others as a tutor for the Mizuki household. He cooperates with Sora and his friends... and has gradually begun to feel that they are precious comrades. Hiding his true identity as Kamen Rider Lido, he observes Sora for the benefit of the Alliance.

30 A man with a dignified, sharp gaze, wearing an impeccable long black coat. The leader who reigns at the top of the Zodiac Alliance, possessing a cold and ruthless strictness. An archenemy who appears before Sora as Kamen Rider Maoh, cornering him with overwhelming power.

55 An elderly man with short, graying hair who favors well-worn work clothes. A benefactor who gave Sora his power as an engineer; he is compassionate and particularly soft on Yuna. A reliable collaborator who puts Sora and Yuna's safety first, providing precise advice from their base.

19 A woman with short black hair and inorganic eyes that make it impossible to read her emotions. The "Rabbit" of the Zodiac Alliance, she moves with a focus solely on rationality and efficiency. While hunting Mysteries as Kamen Rider Datto, she attempts to eliminate Mice whenever he gets in the way.

20 Characterized by spiky hair, a bellicose grin, and a flashy red jacket. A hot-headed battle maniac who finds pleasure in the act of fighting itself. A problem child who transforms into Kamen Rider Jao to attack Mice, only to be disciplined by Maoh.

22 A young man with gentle, drooping eyes who always carries an old book in his hand. He has a mild personality and dislikes conflict, but strives to remain loyal to the Alliance's mission. He operates as Kamen Rider Vanken, but his important Ride-Ex is stolen by Sora.

18 A woman with wavy black hair who is always rubbing her sleepy eyes. She cares for her comrades but is rough in speech and behavior, becoming especially heated regarding Vanken, whom she trusts. She transforms into Kamen Rider Muton and harbors a fierce hostility toward Sora for stealing the Ride-Ex.