Sarina Sonoda

'Sarina Sonoda' (園田 紗里奈) is a classical literature teacher at Amanogawa High School who is also Gentaro Kisaragi, Kengo Utahoshi, and Yuki Jojima's homeroom teacher. It is later revealed that she is the human identity of the Scorpion Zodiarts (スコーピオン・ゾディアーツ), a Horoscopes who distributes Zodiarts Switches among the students. Much of Ms. Sonoda's background story in the series is revealed in the Kamen Rider Fourze the Net Edition: Everyone, Let's Go to Class! Net Movies.

Kamen Rider Fourze
Prior to the start of the series, Sarina Sonoda was once a AGHS student until she met Kouhei Hayami and became the Canis Minor Zodiarts through a Zodiarts Switch he gave her. After several uses, the Switch entered its Last One State. In order to fully evolve, Sonoda threw away her humanity and her Switch and Zodiarts form evolved into the Scorpion Zodiarts.

From there, now a member of the Horoscopes, Sonoda became a teacher as she proceeds to find ideal students that would have the potential to become the remaining eight members. She first introduced Gentaro to the class on his first day, expressing her dismay of both him and Kengo leaving class as she would occasionally speak with Mr. Ohsugi about them and the eventual members of Kamen Rider Club. Ms. Sonoda would later assume her Zodiarts form to fight off Kamen Rider Fourze to keep him from meddling Chameleon Zodiarts' revenge on Miu during the Queen Festival. After Chameleon's defeat; Ms. Sonoda is told not to destroy Fourze by Gamou, believing he can facilitate the Zodiarts' evolution.

Since then, as the Scorpion Zodiarts, Ms. Sonoda oversaw Unicorn Zodiarts's progress before his defeat and aided Teruhiko Satake after giving him the ability to become Hound Zodiarts. During the Altar Zodiarts incident, warned by the Virgo Zodiarts not to get too close to Gamou for her own good, the Scorpion Zodiarts offered Tomoko a Zodiarts Switch. But during the Pyxis incident when she attempted to keep the Kamen Rider from ruining the Pyxis Zodiarts's murderous plan, the Scorpion Zodiarts finds herself outmatched by Fourze's Fire States as she barely escaped by using her cape to absorb the attack.

Later, now allowed to kill Fourze without restraint, Ms. Sonoda is assigned the task to tempt Toshiya Miura back into using a Zodiarts Switch, knowing the powerful addiction the former Orion Zodiarts now had. But Fourze's inference forces her to fall back by creating Dustards that she sends to kidnap Miura the next day. But the Kamen Rider Club's intervention forces the Scorpion Zodiarts to inject her venom into Gentaro so she can fulfill her mission. However, Miura remembers what Gentaro told him about his life before becoming a Zodiarts and rejects the Zodiarts Switch and Gentaro came back to help after being cured from the poison thanks to Kengo and the Medical Switch. Enraged, the Scorpion Zodiarts uses the power she recently received from Gamo to become Scorpion Nova. Fourze manages to get the monster into outer space and defeats her with the Rider Rocket Drill Great Space Kick, sending her crashing back down into Earth uncermoniously. Left unconscious after impact, Ms. Sonada is spirited away by Hayami while he uses his Libra Zodiarts form's powers to cloak her in Gentaro's form to keep her identity a secret.

Relieved of the Scorpion Switch for her failure, Ms. Sonoda is forced to watch from the sidelines as Hayami educates her on their mission during the Perseus Incident. At that time, Ms. Sonoda had the chance to give Yuuki Jojima a Zodiarts Switch but had second thoughts of it due to the girl reminding her of herself at that age. But with the sudden appearance of Kamen Rider Meteor during the Lynx incident, Ms. Sonoda manages to convince Gamou to give her a second chance and fights alongside Hayami in their Zodiarts forms against Fourze after he destroyed the Lynx Zodiarts.

They managed to pressure the lone Rider until Meteor arrived and easily defeated her. Forced back into her human form, the Libra Zodiarts did not bother to mask her identity (though at least kept her face out of sight) as he spirits her back to Gamou's lair where she learns that she is of no more use to him and will be exiled into the Dark Nebula. Begging for another chance, Ms. Sonoda is horrified when the Virgo Zodiarts arrives to carry out the deed. Sucked into the vortex conjured by the Virgo Zodiarts, only Sarina Sonoda's Scorpion Switch remains on Earth. Gamo and his followers proceeded to cover up Ms. Sonoda's disappearance by stating that she was on leave due to a health condition before making her early retirement official.

It is later revealed that, like other persons sent the Dark Nebula by Virgo Zodiarts, she was sent into suspended animation in the M-BUS.

Ama High Graduation
In the novel Kamen Rider Fourze: Ama High Graduation, it is revealed that shortly after the end of the series, Sonoda was returned along with the other M-BUS captives by Fourze Cosmic States.

Super Hero Taisen Z
The Scorpion Zodiarts was one of the monsters in the Space Shocker army which fought a combined force of Kamen Riders, and  as they approached the. It engaged, and was eventually destroyed by his Gavan Hyper Dynamic finisher.

Kamen Rider Wizard
Scorpion Nova's defeat at the hands of Fourze was shown in a recollection by Amadum as he explained the nature of his world as a paradise for monsters destroyed by the Kamen Riders.

All Kamen Rider: Rider Generation 2
The Scorpion Zodiarts appears as a monster in the video game All Kamen Rider: Rider Generation 2.

Personality
Sonoda has a kind and gentle demeanor which made her popular with the students of AGHS. She believes in a friendly approach to the students in contrast to Chuta Ohsugi. As a part of Mitsuaki Gamo's inner circle, her task is to encourage individuality among students. However this pleasant personality is just a farce, getting students to talk out their problems to her so she can distribute Zodiarts Switches to them in her Horoscopes form if their plight is dark enough.

As the Scorpion Zodiarts, Sonoda reveals her more brutal and manipulative nature. She uses the switchers' desire for personal vengeance against another student or the school to become Zodiarts. By knowing the student, she can determine which of them have the potential to make their Zodiarts form evolve and become more powerful. However, as none of her Switchers have ever made it past Last One, she is either choosing the wrong Switcher, or just handing them out in a random pattern in hopes of getting someone able past Last One, like her teacher is able to do.

The Scorpion Zodiarts is not above using a former Zodiarts to become a Zodiarts again despite their protests, even to the extant of taking them by force. Among the Horoscopes, Sonada is the most loyal to Gamo and his cause; effectively being his right hand and living only to meet his expectations.