Mitsuaki Gamou is the leader of the Horoscopes and the main antagonist of Kamen Rider Fourze.


During the summer of 1969, in conjunction with the Apollo 11 exploration, Gamou learned of the Presenters, a alien race from another world. Promising to meet the Presenters one day, it drove Gamou became astronaut with connections to both NASA and the Russian Federal Space Agency before joining the OSTO, becoming "friends" with Rokuro Utahoshi and Kuniteru Emoto as they researched the powers of Cosmic Energy.

But when they received the Core Switch from the Presenters, not agreeing with Rokuro's notion to devise the Fourze system that would be completed within several generations, Gamou reverse engineered the means for a human to rapidly evolve into a Zodiarts with a body that resist the strains of transwarp travel. Once they were finished, Gamou had Emoto steal the Zodiarts Switches from Utahoshi before the OSTO Space Station exploded. From there, with funding by Foundation X, Gamou built Amanogawa High School directly under an atmospheric vortex known as The Hole under the notion that the school is ostensibly foster space exploration in future generations. But in reality, Gamou masterminded the conditions to create the twelve Horoscopes switches so he can execute the Day of Awakening to reach the Presenters despite the resulting devastation.

For the first half of the series, Gamou remained on the sidelines and observed the events that unfold during the course of AGHS's summer and fall semesters, doing his best to keep prying eyes away from his schemes. But when Emoto's true colors and his aiding the Kamen Rider Club are revealed, Gamou assumed his Sagittarius Zodiarts to take out his only friend out while defeating Kamen Riders Fourze and Meteor. Eventually, when Ran Kuroki is identified as the final Horoscopes member, Gamou reveals himself to the Kamen Rider Club and states his ideals.

But when he is about to invoke the Day of Awakening, Gamou finds himself unable to use the Horoscopes Switches due to Kengo as he is revealed to be the Core Child, the manifestation of the Core Switch. But once crushing the Core Switch that maintains Kengo's life in his Sagittarius Nova form, Gamou believed he will have no more interference and announced the end of the world to the entire school on the first day of the spring semester. However, Sagittarius Nova finds himself facing Kamen Rider Fourze before being taken to the school gym where the Kamen Rider Club members hold a "graduation ceremony" as Sagittarius Nova is defeated by Fourze's Youthful Galaxy Great Great Great Drill Kick attack.

Upon finally accepting Gentaro's friendship, Gamou's body begins to evaporate into Cosmic Energy and asks Gentaro to take his place in meeting the Presenters. In his final moments alone, using the Aquarius Switch to repair the Core Switch and revive Kengo, Gamou fades into Cosmic Energy as he apologizes to the Presenters for failing to honor his promise but assures the aliens that his students will come to them in his stead.

Super Hero Taisen Z

During the events of The Sagittarius Zodiarts (With none of Gamou's Personality) was one of the monsters in the Space Shocker army which fought a combined force of Kamen Riders, Super Sentai teamsIcon-crosswiki and Space SheriffsIcon-crosswiki as they approached the Genmu CastleIcon-crosswiki. It was seen fighting Gokai RedIcon-crosswiki. The Space Shocker force was soon destroyed.

Kamen Rider Battride Wars

Sagittarius Zodiarts

Sagittarius Zodiarts in KR Battride Wars

The Sagittarius Zodiarts appears as a boss in the video game Kamen Rider Battride Wars.


Gamou is described by Emoto to be like the sun, a radiant figure of great intellect whose stubbornness can harm those closest to him. He is very reserved and metaphorical. Though friends with Rokuro and Emoto, Gamou never truly was a friend of anyone as the concept was of no true importance to him. He seems to take pride in his role as an astronaut, using space metaphors in his speech and stating to the Kamen Rider Club that his desire to see the Presenters for the sake of exploring the unknown and evolving beyond humanity is a justified reason for his actions.

Even since hearing from the Presenters when he was a child, he made meeting the Presenters as soon as possible his lifelong goal, fully willing to use and sacrifice just about anything and anyone to see his goal fulfilled. As such, while he appears to be benign most of the time, he is certainly amoral.


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Sagittarius Constellation seen in Gamou's body by the Libra Zodiarts' Eye of Laplace

Gamou himself is shown to possess supernatural powers such as giving a member of the Horoscopes the ability to assume Supernova form, and the ability to conduct hypnotic suggestion that he uses on outsiders to drive them away, thus keeping his true agenda a secret from prying eyes. Like Tatsugami, he also sports an unique physique which allows him to use any manifested Zodiarts Switch.

Dark Nebula

Sagittarius evoking the Dark Nebula

Once obtaining all twelve Horoscopes Switches, Gamou can evoke the Dark Nebula on command and use it to travel the cosmos. However, the power of the Dark Nebula would have caused the destruction of Japan in the process.


Sagittarius Zodiarts

As the unnaturally durable Sagittarius Zodiarts, Gamou has a form of telekinesis that he uses to paralyze people should they try to get in the way. He is armed with a powerful bow on the left forearm called Gilgamesh, which can unleash a barrage of fiery Cosmic Energy-made arrows called Apostolos. While normallly closed, it will open if it absorbs large amounts of energy, like fire for example. Gamou can then release exponential amounts of energy arrows by drawing back a string made from the same energy and letting it loose an absurd amount of arrows all at once. These arrows are always accurate, and seem to be able to home in on their targets, such as Meteor's Storm Topper.

KRF-Sagittarius Nova

Sagittarius Nova

Once he goes Supernova, he obtains the form known as Sagittarius Nova, where he trades his huge bow and heavy armor for a much lighter body. In this state, Gamou can perform a flying kick attack, similar to a Rider Kick, with his leg surrounded by an aura of Cosmic Energy resembling an arrow. He can also throw a Rider Punch-like attack.

He can still shoot arrows in this form, however, so he still remains a threat at all distances.

Aquarius Zodiarts

Aquarius Zodiarts

  • Height: 231 cm
  • Weight: 187 kg

By using the Aquarius Switch, Mitsuaki can transform into the Aquarius Zodiarts.

Mitsuaki used this form to restore the Core Switch and revive Kengo Utahoshi in Finale: Youthful Galaxy.

Musical Themes

Gamou has two leitmotifs: "The Red-Eyed Man" which is prominent in scenes when he meets with the Horoscopes, and "Fear the Power" that plays while he in his Horoscope form.


The kanji that comprises Gamou's given name can be translated as "bright light", which is one of the epithets of the Greek god Apollo. Apollo also was the god of archery, linking Gamou to Sagittarius the Archer. Gamou's Zodiarts form's use of fiery arrows also links him to Apollo, whom is the god of the Sun (which is made of fire.).


  • The Sagittarius Zodiarts has oddly a bird theme despite the sign being that of a centaur archer. The reason is because the secretarybird's scientific name is Sagittarius serpentarius.
    • Hilariously enough, that last bit would also reference Ophiuchus (as Serpentarius is Ophiuchus' old, Latin-based name), which is often considered to be the unofficial 13th sign of the Astrological Zodiac.
  • Sagittarius Nova form bears an amazing likeness to the super robot Gurren-Lagann. One has to consider the fact that the writer of Gurren Lagaan is the head writer of this Kamen Rider season.
           Neo-Heisei Kamen Rider Villains

Foundation X
Neon Ulsland | Jun Kazu | Tabata | Doctor Prospect | Lem Kannagi

Sonozaki Family: Ryubee Sonozaki | Saeko Sonozaki | Wakana Sonozaki | Kirihiko Sudo | Mick

Ankh | Uva | Kazari | Gamel | Mezool | Ankh (Lost) | Kiyoto Maki | Shocker Greeed

Horoscopes: Sagittarius Zodiarts | Virgo Zodiarts | Libra Zodiarts | Scorpion Zodiarts | Leo Zodiarts | Cancer Zodiarts | Aries Zodiarts | Capricorn Zodiarts | Aquarius Zodiarts | Taurus Zodiarts | Gemini Zodiarts

Wiseman | Phoenix | Medusa | Gremlin

Yggdrasill Corporation
Takatora Kureshima | Ryoma Sengoku | Lock Dealer Sid | Yoko Minato | Mitsuzane Kureshima | Oren Pierre Alfonzo | Kurokage Troopers

Overlord Inves
Rosyuo | Redyue | Demushu | Dyudyuonshu

Helheim Forest

Executives: Freeze | Heart | Brain | Roidmude 004 | Roidmude 006 | Medic | Mashin Chaser | Gold Drive
Reaper Legion: Roidmude 013 | Roidmude 015 | Roidmude 019 | Roidmude 021 | Roidmude 022 | Roidmude 028 | Roidmude 032 | Roidmude 034 | Roidmude 035 | Roidmude 044 | Roidmude 045 | Roidmude 054 | Roidmude 059 | Roidmude 070 | Roidmude 075 | Roidmude 081 | Roidmude 092 | Roidmude 094 | Roidmude 100 | Roidmude 101 | Roidmude 104 | Roidmude 105
Other Roidmudes: Roidmude 016 | Roidmude 036 | Roidmude 057 | Roidmude 060 | Roidmude 062 | Roidmude 074 | Roidmude 076 | Roidmude 098