They are the main enemy in Kamen Rider Fourze. They are human beings that use a Zodiarts Switch to transform a monster based on star constellations. There are two types of Zodiarts: ones based on actual constellations and ones based on the Zodiac. The ones based on the Zodiac are called Horoscopes and are much stronger than the typical Zodiarts. The Horoscopes are created from surpassing Last One which separates the human host from the Zodiarts body. If successful in becoming a Horoscope, the human host is remerged with the new Zodiarts form.

Non Horoscopes

Orion Zodiarts

Actual Name: Miura Toshiya 三浦 俊也

Played by: Mizuno Masanori 水野 真典

Miura Toshiya is a second year student and equipment manager of the American Football club at Ama High. He always wanted to play but Shun wouldn't allow him and forced him to be his own personal servant. That frustration lead him to becoming the Orion Zodiarts. He desired to destroy Shun and the school with his new-found power. Fourze took him to space and defeat him with Rider Rocket Space Drill Kick. After Miura recovered from his defeat, he refused to go to school because he would succumb to the power of the Switch again. It took the support of the Kamen Rider Club and his girlfriend, Yamamoto Mari, to overcome the desire for the Switch. Even though he was offered to join the Kamen Rider Club, he decides to join the photography club with his girlfriend.

Orion Zodiarts possess great strength and resistance while producing explosions from his stars. When going to Last One, he gains a club and shield.

Chameleon Zodiarts

Actual Name: Sakuma Tamae 佐久間 珠恵

Played by: Yoshikawa Maria 吉川 まりあ

Sakuma Tamae is a third year student and a member of the cheerleader club at Ama High. She was one of Miu's sidekicks who personally hated Miu for her run as Queen of Ama High. Tamae was given a Zodiarts Switch by Scorpion and became the Chameleon Zodiarts. With her power, she forced Hirota Reiko not to enter Queenfest along with two other girls. During her performance at Queenfest, Tamae pretend to be attacked by Chameleon so she could change and attack the remaining candidates. In case if her attack failed, she setup a hidden camera where Miu was badmouthing the student body and destroying their gifts. She personally attacked Miu a second time which she greatly injures Miu. Tamae thought she had Queenfest won but Miu returns and gives a strong speech that wins over the student body. She kidnaps Miu from the stage which Fourze fights her for one last time. Fourze defeats the Chameleon Zodiarts which Miu forgives Tamae and tells her to defeat her fairly.

Tamae makes a return appearance as former Zodiarts were coming back which Chameleon was one of the returning Zodiarts. She was going to ask Gentarou to prom but he accused her of being Chameleon again. Eventually the Kamen Rider Club figured out that Tamae hasn't become Chameleon but a hair copy from the Coma Zodiarts. She ends up going to prom with Jin.

Chameleon Zodiarts has the power to blend into its surroundings, climb walls, and a tongue that acts like a whip.

Unicorn Zodiarts

Actual Name: Niita Fumihiro 新田 文博

Played by: Uji Kiyotaka 宇治 清高

Niita Fumihiro is a first year student and member of the fencing club at Ama High. He used to a friend of JK until he discovered that he used him to protect him from bullies especially the injuries he received made him unable to appear in a match. He got the perfect chance for revenge when Scorpion gave him a Zodiarts Switch. He constantly attack JK but Fourze kept getting in his way. Eventually he manages to capture JK and tells him if one of his friends shows up within an hour that he will release him. Niita was right about JK for the most part except Gentarou shows up even though JK betray him earlier and calling his idea of friendship foolish. He wasn't going to release JK regardless but ends up being defeated by Elec States. Gentarou tells Niita that he wish he met him sooner so he could stopped him.

Unicorn Zodiarts initially had no special attacks but was able to detach his horn and use it as a rapier. He even can shoot out energy horseshoes.