This article is about a/an main ally in Kamen Rider OOO.
Erika Satonaka
Kamen Rider Birth (Net Movie Only)
Gender: Female
Series: Kamen Rider OOO
Motif: Gashapon
Rider Type: Heroine
Homeworld: Earth (Main Timeline Continuity)
First Appearance: Medals, Underwear, and the Mysterious Arm
Last Appearance: Kamen Rider × Kamen Rider Fourze & OOO: Movie War Mega Max
Number of Episode
48 (OOO)
3 (Movies)
Full list of appearances
Actor: Mayuko Arisue
Satonaka Birth Profile

Erika Satonaka (里中 エリカ Satonaka Erika) is Kosei Kougami's able and beautiful secretary. Later, she becomes Shintaro Goto's assistant when he takes over as Kamen Rider Birth.


Erika is a mature young woman who always faces anything with a calm, sometimes bored, disposition. Despite liking spicy foods better, she puts up with having to eat cakes made by her boss everyday. Because she is always made to eat the cakes that Kougami makes, she always has dieting on her mind. She is quite strict and rigid when it comes to performing her duties, constantly refusing to work over time and working earlier than she should despite having pressing matters at hand that needs immediate attention to.

Despite presenting herself as a bored, duty-bound normal secretary to an abnormal boss in an abnormal company, she is actually quite capable of handling herself in fights and uses a Birth Buster at a weaker setting. She is also quite conscious of her own looks, as when she is made Goto's support when he takes up the mantle as Kamen Rider Birth, she adamantly refuses to start working early and would not go anywhere until she has put on make-up and properly dressed herself, despite such behavior interfering with Goto's battles.

In the Net Movie, it was shown that Goto asked her to not to be rude to Date, but she easily beat up Date and Goto. She also takes Goto's Birth Driver away and transforms into Kamen Rider Birth leaving Goto crying.


Erika often leaves the chairman's office to assist Shintaro Goto in information gathering or to speak to Eiji on Kougami's behalf (though she actually outranks him). Later, she becomes Goto's assistant when he takes over as Kamen Rider Birth, but is lazy and causes trouble for him - showing up late to battles and sending a Gorilla Candroid to assist him in her place.

But in episode 40, Erika becomes a bit more reliable when Shintaro agrees to pay her five percent of his salary to be ready for battle against the Greeed immediately. However, she still causes him grief by throwing him only one spare clip of ammunition for the Birth Buster.

Video Game appearances

Kamen Rider Travelers Record

Satonaka appears in the video game Kamen Rider Travelers Record.

Kamen Rider Birth


  • Height: 199 cm
  • Weight: 92 kg

Ability Perimeters:

  • Punch power: 3.5 t
  • Kick power: 8 t
  • Jump power: 45 m
  • Speed: 100m/5s

She only transforms into Kamen Rider Birth in Net Movie: Kamen Rider OOO Allstars: The 21 Leading Actors and Core Medals after beating up with Goto and Date.

Like Kamen Rider OOO, Kamen Rider Birth's powers stem from the O Medals that power the Greeed and their Yummy creations. However, Kamen Rider Birth's powers originate solely from the Kougami Foundation's technology developed by Kiyoto Maki to utilize the power of the Cell Medals. On Birth's armor there are capsules called Receptacle Orbs (リセプタクルオーブ Riseputakuru Ōbu), in which the Birth CLAWs system is installed in until a Cell Medal is used to summon the weapons. However, due to using Cell Medals as opposed to Core Medals, Birth was at a disadvantage against a single Greeed. Kamen Rider Birth's exosuit has originally a self-destruct function built into it. However, the self-destruct function has been disabled by Shintaro Goto when Kiyoto Maki defected to the Greeeds' side.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.