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

Ritsuko Usaka (鵜坂 律子 Usaka Ritsuko) is a girl who has been blamed for various unexplained incidents in Amanogawa High School due to her tendency to isolate herself and have certain psychic powers, much like Tomoko. She gives into the persecution and becomes the bad girl everyone perceives her to be as she forms her own witches' coven called the Lunar Witches (月世界の魔女 Gessekai no Majo) with other scorned social outcasts.


She is given a Zodiarts Switch by Scorpion Zodiarts, allowing her to transform into the Altar Zodiarts (アルター・ゾディアーツ Arutā Zodiātsu), granting her powerful telekinetic powers via her Aradia (アラディア) staff. However, Ritsuko's passion for the occult evolves her Zodiarts form to also use pyrokinetic powers. Creating moon pendants for her followers to wear, Ritsuko uses her powers to make it appear that she and the members of her group are actually witches before Kengo exposes the deception. By then, using the Zodiarts Switch in its Last One state, the Altar Zodiarts proceeds to enact her plan to burn the entire school to the ground.

When her plan is ruined, she becomes infuriated and overpowers Kamen Rider Fourze in battle. Upon transforming into Firestates, Kamen Rider Fourze absorbs her fire-based attacks before destroying her Zodiarts form with the Rider Exploding Shoot.

She returns later on during the Coma incident, where she once considered taking Gentaro to the dance, but the Rider's questioning hurt her feelings and declined the thought. She was later seen with Ryusei Sakuta, who went with her under a threat from Tomoko.

Kamen Rider Fourze Ritsuko & the lunear witches

Ritsuko & the Lunar Witches


Altar Zodiarts

Altar Zodiarts

The Altar Zodiarts (アルター・ゾディアーツ Arutā Zodiātsu) is the Zodiarts form associated with the constellation of Ara. She can emit fire from her head and has a wand that can telekinetically control objects, enemies, and herself.

  • Height: 219 cm
  • Weight: 180 kg

Behind the scenes


Ritsuko Usaka is portrayed by Hikari Kajiwara (梶原 ひかり Kajiwara Hikari), who previously portrayed Amane Kurihara in Kamen Rider Blade.

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

Community content is available under CC-BY-SA unless otherwise noted.