Name: Sora Otosumi. Age: 21. Title: Meister (Butler/Servant) to the Misumaru family. Personality: Quiet and always composed. He is polite and performs his duties perfectly, but beneath the surface, he hides a passionate sense of justice and a resolve to risk his life to protect his Mistress. Sora himself possesses exceptional hearing and agility. He excels at a fighting style that senses the enemy's slightest movements to toy with them.

Name: Kamuri Minetaka. A man awakened from a 100-year slumber. Leader of the "Zodiac Alliance," an organization formed to fight the monsters known as "Fukashigi." He transforms by loading items into his unique transformation belt, the Maou Driver. He uses a large sword called the Maou Blade as his dedicated weapon. Overwhelming charisma and strength: He possesses the charisma to lead the eccentric members of the Zodiac Alliance and boasts combat power that stands out even among the Kamen Riders in the story. While he has a whimsical side, his actual ability is overwhelming. The "Cat" Rider: Reflecting the Zodiac legend (where the cat was tricked by the rat and arrived late to the God's gathering), he embodies the "Cat" that was excluded from the Zodiac. Because of this, he is in a fated rivalry with the protagonist Sora Otosumi (Kamen Rider Mice), whose motif is the Rat.

Ecology of preying on and mimicking humans: The Fukashigi do not just attack and eat humans; they possess an extremely troublesome and intelligent trait of mimicking (transforming into) the humans they have eaten to infiltrate society.

Classical character traits: Usually dressed formally in a three-piece suit and glasses, but at the organization's headquarters, he prefers retro clothing reminiscent of the Taisho to early Showa eras, such as an Inverness coat with black fur. While he has a serious personality, he often gets dragged along by those around him (like Yuna) and makes charming mistakes to keep things from getting too grim. Fighting style: A combat style combining karate with supple, swift movements. Under the orders of Kamuri Minetaka, Tatsuomi Asao infiltrates the Mizuse household as a "private tutor" to investigate the secrets of the protagonist, Sora Otosumi. Transformation system: He transforms (undergoes metamorphosis) by setting the Hammer Bone Buckle into the Mice Driver and loading/smashing the Ride Ex 1.