This article is about a/an villain turned ally in Kamen Rider Fourze.

Haru Kusao (草尾 ハル) is a meek new first-year student at Amanogawa High School who receives a Zodiarts Switch from Libra and becomes the Musca Zodiarts (ムスカ・ゾディアーツ Musuka Zodiātsu). The reason why he wanted the Switch was to protect his (for a long time, only) friend Ran.

She had long sworn to protect him, after an incident where upperclassmen at their previous school threw Haru's friendship charm with Ran's name on it into the pool and teased him, but she stood up for him and retrieved the charm, thus gaining a disdain for upperclassmen. However he had gotten a high off the switch, and still saw Ran trying to protect him (as both himself and the Musca Zodiarts), leading to an increasingly unstable mental state.

However, his power to convert his body into a swarm of flies was negated when Fourze used the power of the Net Switch onto Musca, forcing the Zodiarts to stay solid while Fourze assumed Magnetstates. However, Kengo warned that if Haru's Zodiarts form was destroyed while he was mentally unstable, he would remain that way. Just then, Ran yelled to Haru an apology for trying to protect him when he didn't want protecting. Haru's heart was reopened, and he asked Gentaro to send him back to his body, and was blasted away by a Super Electromagnetic Bomber.

Later, after returning to his body, Haru is given provisional membership alongside Ran while recuperating from his injuries in the hospital. However, Haru was used by Leo to bring out Ran, who was the last Horoscopes, Pisces. By the end of the series, Haru and Ran become official members of the renamed Space Kamen Rider Club.



Main article: Astroswitches

In the movie Kamen Rider Fourze the Movie: Everyone, Space is Here!, he used the Net Switch as a relay to help create the Fusion Switch.

Musca Zodiarts (Infinite Monster Plant)

A second Musca Zodiarts, already evolved to its final stage, is created by the Akumaizer's Infinite Monster Plant (無限モンスタープラント Mugen Monsutā Puranto) in Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum. It fights against Kamen Rider Double, but is easily destroyed with a standard flying kick.

Super Hero Taisen Z

The Musca Zodiarts is one of the revived monsters that join Space Shocker, but it's seemingly defeated once again. It's seen for the last time fighting against the Super Sentai team Flashman.

The Fateful Sengoku Movie Battle

to be added

Musca Zodiarts

Musca Zodiarts Phase 1

Phase 1

  • Height: 223 cm
  • Weight: 180 kg

It can spit a sticky mucus-like slime from its mouth and can jump high. This form known retroactively as "Phase 1" (フェーズ1 Fēzu Wan).

Musca Zodiarts Phase 2

Phase 2

  • Height: 223 cm
  • Weight: 180 kg

The Zodiarts reacts to Haru's emotions and desire to become stronger and undergoes a metamorphosis that gives him neon green armoring on his forearms and shins that increase Musca's physical power [this form being known as "Phase 2" (フェーズ2 Fēzu Tsū)], though that was proven no more then decorative to the more adept Kamen Riders.

However, Musca soon gained the ability to convert his body into a massive swarm of flies when fighting Fourze in Elekstates, though he couldn't control himself while doing so.

Musca Zodiarts Phase 3

Phase 3

  • Height: 223 cm
  • Weight: 180 kg

Once Haru hit the Last One phase, Musca had turned into a terror that is "Phase 3" (フェーズ3 Fēzu Surī). On top of his previous abilities, Musca gained better and spiked armor, allowing him to withstand more punishment. It also gained wings, allowing Musca to fly, and the projectile slime turn into rainbow-hued slime balls that explode upon impact.

However, his power to convert his body into a swarm of flies was negated when Fourze used the power of the Net Switch onto Musca, forcing the Zodiarts to stay solid while Fourze assumed Magnetstates.


  • Haru being the Musca Zodiarts may be reflected in his name, which is one letter removal away from becoming the vulgar word "Kuso", which can be translated into "crap" in English.
  • Haru is the first character to be revealed that one of the Members of Horoscopes is from school faculty.
Icon-fourze Kamen Rider Fourze
Kamen Riders
Gentaro Kisaragi - Ryusei Sakuta - Nadeshiko Misaki
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
Yuki Jojima - Kengo Utahoshi - Miu Kazashiro -Shun Daimonji -Tomoko Nozama -JK - Chuta Ohsugi
Other Ishinomori Heroes
Inazuman* - XVII*
The Zodiarts
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

Other Villains

Lem Kannagi - Akumaizer

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