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Icon-fourze.png This article is about a villain in Kamen Rider Fourze.

Tatsumori Yamada (山田 竜守, Yamada Tatsumori) is a 3rd year transfer student from AGHS to Subaruboshi High School. He is also the Aries Zodiarts (アリエス・ゾディアーツ, Ariesu Zodiātsu), a Horoscope with terrifying abilities, who had evolved from the Lepus Zodiarts (レプス・ゾディアーツ, Repusu Zodiātsu).


Like Kijima, Tatsumori looks more innocent than he actually is. He appears to be well-spoken and mild-mannered. Underneath the surface, he is a psychopathic control freak, and will punish anyone who does not follow him.

He treats Subaruboshi High School as his theatrical troupe, as he decides the casts and story, and anyone who defy him will be put to sleep. He have no interest of joining the Horoscopes and just wants to rule over Subaruboshi High School, as this is the place where he was evolved into the Aries Zodiarts. Tatsumori is also manipulative, bribing Ryusei Sakuta with a deal to save Jiro Iseki if Ryusei kills Fourze.


Yamada began as a transfer student at SBHS who was originally a quiet member of AGHS's drama club. However, upon arriving to Subaruboshi High, Yamada used the Zodiarts Switch he obtain to become the Lepus Zodiarts before evolving into the sixth member of the Horoscopes, the Aries Zodiarts. He abuses his ability to put people to sleep and developed a god complex, to the point of totally disregarding the Horoscopes' interest in general.

Yamada transfers to Subaruboshi High to break away from the director's scrutiny, and took on the title of "The Apostle of Sleep" as he gets the entire school under his control and has everyone act in the roles he assigns them. Though Ryusei was only looking for the Aries Zodiarts under Tachibana's orders initially, he now sees a way to save Jiro in the said Zodiarts.

As a result, against Tachibana's orders, Ryusei decides to make a deal with Yamada, by killing Kamen Rider Fourze, to save Jiro. He was later defeated by Kamen Rider Fourze in Cosmicstates and his Switch was taken by Virgo. He is last seen in a hospital, ironically in a coma.


Lepus Zodiarts

Tatsumori's original Zodiarts form, here his appearance resembles a rabbit but still, his original powers was never revealed as received the Switch but pressed it once during his student exchange program and at the same time evolving into Aries Zodiarts. Subaruboshi Kingdom

Powers and Abilities
Once Lepus Zodiarts entered his Last One state and turned red, he can simply evolve into a Horoscope.

Aries Zodiarts

Aries Zodiarts (cloaked)

  • Height: 235 cm
  • Weight: 209 kg
Powers and Abilities
Horoscopes can teleport themselves to any desired places.
Dustard Creation
Horoscopes can create Dustards by from Stardusts.
Supernova (超新星, Chōshinsei)
The signature power of Horoscopes, using this can either assume a more powerful form or gain a new technique.
Coppelius Scepter (コッペリウスセプター, Kopperiusu Seputā).
A coma-inducing staff and is alternatively referred to as the Apostle of Sleep (眠りの使徒, Nemuri no Shito) because of this power. This works both ways, as he can also pull people out of comas, hence why Ryusei Sakuta is desperate to find him. His powers can also be transferred to various parts of the body, such as shutting down Gentaro's left arm and right leg, which briefly disabled his ability to use Astroswitches of those limbs until he succumbed to sleep.

Aries Nova

  • Height: 235 cm
  • Weight: 209 kg

The Aries Zodiart briefly transformed into Aries Nova (アリエス・ノヴァ, Ariesu Nova) due to desire for power, losing his cape and extending his horns.

Powers and Abilities
Aries Nova can shoot fireballs from his horns.

Behind the scenes


Tatsumori Yamada is portrayed by Kazuma Kawahara (川原 一馬, Kawahara Kazuma), who previously portrayed Mutsuki Kuroha/Kamen Rider Leangle from Kamen Rider Decade's World of Blade arc.


The kanji that make up his given name (竜守, Tatsumori) translate into "dragon guard", referring to the dragon that had guarded the Golden Fleece (the basis of Aries), until it was lured to sleep by Medea, as so the Greek hero Jason could steal it, during the time of the Argonauts.


  • Tatsumori's sleep-based special ability, not to mention his Zodiarts form's animal motif, refers to the idiom "counting sheep".
  • His defeat by Gentaro is poetically karmic. He used his powers as the Aries Zodiarts to put his enemies to sleep and go so far to manipulate Ryusei into killing Gentaro, which ultimately leads to his defeat by Fourze Cosmicstates, ironically leaving him in a coma.
Icon-fourze.png Kamen Rider Fourze
Kamen Riders
Gentaro Kisaragi - Ryusei Sakuta - Nadeshiko Misaki - Kamen Rider Ikaros - Rider Hunter Boot
Fourze Driver - Meteor Driver- Nadeshiko Driver - Astroswitches - Astroswitch Case - Billy the Rod - Hee-Hackgun - NS-MagPhone - Meteor Galaxy - Barizun Sword - Meteor Storm Shaft - Machine Massigler - Machine Meteorstar - Powerdizer
Kamen Rider Club
Initial Members
Yuki Jojima - Kengo Utahoshi - Miu Kazashiro - Shun Daimonji - Tomoko Nozama - JK - Chuta Ohsugi - Ran Kuroki - Haru Kusao
5 Years After
Saburo Kazeta - Rumi Komaki - Daita Kondou - Chikao Nezu - Miyoko Ohki
Ishinomori Characters
Inazuman - XVII - Skydain - Groundain - Black Knight - Inga Blink
The Horoscopes: Sagittarius - Virgo - Leo - Libra - Scorpio - Cancer - Aries - Capricorn - Aquarius - Taurus - Gemini - Pisces

Zodiarts: Orion - Chameleon - Unicorn - Hound - Altar - Pyxis - Perseus - Lynx - Dragon - Pegasus - Cygnus - Coma - Musca - Hercules - Lepus

Stardust Ninja Dustards
Foundation X
Lem Kannagi - Katal - Solaris - Chancellor Kiima - Suddendath Beta
Xatan - Eel - Gahra