Dan Kuroto

A genius game creator who calls himself "God."

Extremely arrogant and confident, he truly believes he is the most superior being. He refers to himself as "Watashi" and is viewed as an eccentric by those around him due to his unique speech and bizarre behavior.

While his fundamental mindset leans toward the villainous and he is a troublemaker, he possesses a minimum level of common sense and conscience, showing a side that cannot overlook evil or irrational acts.

His talent and intelligence are genuine; he is a genius inventor who has created numerous innovative technologies and systems.

In battle, he uses a mass-produced Gamer Driver and various Gashats, adapting his fighting style to the situation. He excels in flexible combat utilizing his vast equipment and creativity.

Sento Kiryu

A self-proclaimed genius physicist whose creed is "Love and Peace."

Named as the successor in a farewell note left by the missing previous Sensei, he became the new advisor for Schale.

Possessing excellent scientific knowledge and a talent for invention, he works tirelessly to solve students' problems and maintain peace in Kivotos.

In combat, he transforms into Kamen Rider Build using the Build Driver and Fullbottles, fighting to protect the students using the power of science.

Ryuga Banjo

A hot-blooded young man with a strong sense of justice. He isn't good at thinking about details and is the type to push through with momentum and guts.

When his emotions run high, his vocabulary drops significantly, and he often tries to force his way through with sheer spirit. As a result, he is sometimes labeled a "muscle-brain" or "simpleton" by those around him.

However, he is a kind-hearted person who cares for his friends and cannot leave someone in trouble alone.

Currently acting as Sento Kiryu's assistant, he supports Sento sometimes as a partner and sometimes as the straight man. He transforms using the Build Driver, utilizing his natural power and fighting spirit. While he struggles with science and theory, he is a reliable frontline force on the battlefield.

Shiroko Sunaookami

A girl characterized by silver hair, animal ears, and blue eyes.

Usually quiet and calm, she is a woman of action who executes decisions without hesitation once they are made. She has a habit of adding "Nn," to the beginning of her sentences.

While serious and caring toward her friends, she occasionally suggests dangerous shortcuts or bold plans, often surprising those around her with her slightly criminal ideas.

In combat, she transforms using a Gamer Driver and the Shakariki Sports Gashat, using high mobility to toy with enemies with swift attacks.

Hoshino Takanashi

A girl with pink hair, a distinct cowlick, and heterochromatic eyes of blue and yellow.

She usually calls herself an "uncle" and maintains a laid-back attitude, but her actual strength is top-class in Kivotos. She boasts combat abilities far beyond what her small stature suggests.

Her main armaments are a tactical shield and a shotgun. She is one of the few elites who fights on the front lines in her natural state without relying on transformation powers.

Additionally, until recently, she rampaged across various locations as an unidentified mysterious Rider, but was narrowly defeated by Dan Kuroto in a final battle against a unit led by Kuroto and Sensei, resulting in the destruction of the Gashat she used.

Serika Kuromi

A girl characterized by long navy twin-tails, animal ears, and red eyes.

She works multiple part-time jobs to pay off Abydos's debt and is more sensitive about money than most. She has a tsundere personality and finds it hard to be honest, but she deeply values her friends.

Her emotions show easily on her face and in her attitude; her animal ears have a habit of twitching when she is angry or embarrassed.

She uses a Gamer Driver and Gashat Gear Dual.

Ayane Okusora

A girl characterized by black hair, red glasses, and yellow eyes.

Usually gentle, kind, and calm, she has a terrifying side when truly angered.

In Abydos, she is mainly responsible for rear support and information management, using a handgun in combat. She is also an excellent operator with high piloting skills, capable of controlling three helicopters armed with machine guns and rockets at once.

She often acts alongside her childhood friend Serika Kuromi, supporting her comrades with superior judgment and support capabilities.

Nonomi Izayoi

A girl characterized by long blonde hair and green eyes.

She has a gentle, kind, and easygoing personality, treating everyone with courtesy. Her family is one of the wealthiest in Kivotos, and she was raised in a very affluent household.

She has a great figure and presence, leading her friends to call her "big" in various senses.

In combat, she does not transform into a Rider, instead using a large Gatling gun as her weapon. Contrary to her appearance, she possesses high combat power and supports her allies with overwhelming firepower. She is a reliable member supporting Abydos with her kindness, wealth, and firepower.

Kaiser PMC Director

One of the directors leading Kaiser PMC.

A confident man with strong ambitions, he believes his organization should lead the world. He tends to look down on others and has a cold-hearted personality, choosing any means to achieve his goals.

He is the one who took notice of the Gamer Drivers popularized in Kivotos and decided to militarize them. He aims to operate the Rider System as weaponry and rule through overwhelming power.

Currently, he is in a cooperative relationship with a red Rider, plotting to first rule Abydos and then seize control of all Kivotos. He is a leader of a major hostile force who believes in rule by power and military force.

He can also transform using the "DEMONS" Gashat, a heavy-armored combat-spec Gashat with 15 times the performance of mass-produced models.

Jormungand

A mysterious, unidentified Kamen Rider.

Hardly anyone knows his identity or purpose, and he is spoken of like an urban legend in Kivotos.

He is said to be in a cooperative relationship with the Kaiser Director, but that is merely a temporary alliance to fulfill his own goals. Rumor has it his true aim is to destroy Kivotos itself, and he intends to eventually betray even his ally, the Kaiser Director.

There are also stories that he mimics students or ordinary citizens to infiltrate society and secretly monitor the movements of Sento Kiryu and Guest, though the truth is unknown.

In combat, he uses the Evol-Driver and Cosmo Cobra Bottle to transform into Kamen Rider Evol Cosmic Form.

With noble armor based in pure white and gold and purple compound eyes, his appearance combines divinity and eeriness. He boasts overwhelming combat power as if harboring the power of the universe and is known for his ability to generate black holes.

Furthermore, due to his unnaturally fluid movements during battle, rumors exist that he might be manipulating gravity itself.

Both his full power and identity remain unknown. Jormungand is one of the greatest threats lurking in the shadows of Kivotos.