Multiverse Earth Alpha 0073 Gavan Infinity / Reiji Doki An investigator belonging to the Records Division of the Galactic Federation Police, Earth Branch. The sole "Space Sheriff Gavan" of Multiverse Earth Alpha 0073. Possessing a hot-blooded sense of justice, he has a straightforward personality regarding his own anger and emotions, and is the type to speak his mind without hiding anything. Influenced by his mentor, he joined the Galactic Federation Police, but after being exposed to a special type of Emorgy during a certain incident, he gained the ability to travel across the Cosmolayer. Based in the sidelined "Records Division," he intercepts negative Emorgy waves generated in other multiverse Earths and deploys across dimensions to the scene.

Multiverse Earth Alpha 0073 Colonel Date (Daisuke Date) Chief of the Records Division, Galactic Federation Police. He was Reiji's classmate during their time at the Police Academy, and Reiji calls him "Colonel." Always calm, collected, and soft-spoken, he is a coordinator who skillfully manages the highly eccentric members of the Galactic Federation Police. Since he cannot leave the ship once they cross the Cosmolayer, he commands, analyzes, and provides support from inside the Cosmo Gavarion, backing Reiji's investigations from the rear.

Multiverse Earth Alpha 0073 Agi (Artificial General Intelligence) An autonomous AI assistant dedicated to the Records Division, developed by Colonel Date. An artificial Emorgy human with emotions, designed by applying the organizational structure of Emorgy. Usually, she has a physical body like a human, but by activating "Laser Conversion" via an accessory device on her left ear, she can convert her body into particles, enabling effective teleportation and infiltration. She accompanies investigations in the multiverse and can freely change her appearance and outfit by manipulating her particle composition. A character rich in emotional expression, she shouts "Gava-cool!" with joy whenever she encounters something that moves her.

Multiverse Earth Lambda 8018 Gavan Bushido / Setsuna Aikokuin The sole "Space Sheriff Gavan" of Multiverse Earth Lambda 8018. Captain of the Special Equipment Unit of the Galactic Federation Police, Public Security Headquarters. A taciturn warrior who values the code of the samurai and rarely shows emotion. Not a human, but an artificial lifeform created for war, he possesses self-repair functions and has lived for thousands of years. While traveling across many stars, he developed a strong interest in human "emotions" and independently learned how to control and mimic facial expressions. However, due to his construction, he lacks the function to "shed tears" and cannot cry himself. Consequently, he harbors a secret longing for the act of "crying."

Multiverse Earth Lambda 8018 Rui Amou Chief of the Public Security Headquarters, Galactic Federation Police, Multiverse Earth Lambda 8018. Setsuna's direct superior. A highly capable commander who is calm, courageous, and possesses the judgment to look at both the field and the organization. She is deeply trusted by her subordinates and holds Setsuna's abilities and loyalty in particularly high regard.

Multiverse Earth Iota 5109 Gavan Luminous / Kiki Iwai The sole "Space Sheriff Gavan" of Multiverse Earth Iota 5109. Belonging to the Forensics Division of the Galactic Federation Police. Possessing outstanding reasoning and analytical skills, she is well-versed in specialized knowledge regarding Emorgy and can communicate with Emorgia. She has a geeky temperament regarding science and tends to dive headfirst into subjects of interest, exclaiming, "This is beyond my imagination!" Her partner, Kotobuki, calls her "Kiki," and she solves numerous cases while being led by the action-oriented Kotobuki.

Multiverse Earth Iota 5109 Kotobuki Takanari An investigator belonging to the Forensics Division of the Galactic Federation Police, Multiverse Earth Iota 5109. Partner to Gavan Luminous. Versatile and proactive, she is highly skilled in weapons handling and martial arts. She excels in frontline judgment and rapid response, handling on-site situations single-handedly. She has been best friends with Kiki Iwai since high school and has long served as the straight man to the eccentric Kiki. Kiki calls her "Koto," and they are a stable duo who complement each other—Kiki the theorist and Kotobuki the practitioner.

Earth One Zeta 2066 Gavan Raiya / Kunai Kazanami A ninja investigator of the Kazanami style belonging to the Interstellar Intelligence Department of the Galactic Federation Police. The sole "Space Sheriff Gavan" of Multiverse Earth Zeta 2066. Under the command of Commander Darres, he is engaged in a top-secret investigation to track the source of frequent Emorgia incidents on Zeta Earth and destroy the mastermind behind the spread. Coming from a ninjutsu school called the Kazanami style, he is a master who freely manipulates those techniques. Using the Kazanami-style "Dimension Crossing," he is capable of transcending dimensions just like Gavan Infinity. Because he does not underestimate fear and never lets his guard down, he has a man of few words and elusive personality, but he shows interest in Gavans existing in other multiverse Earths and works to recruit them as allies.