This is the character list of 2021 Ultra Series Ultraman Trigger: New Generation Tiga, as well as the 2022 follow-up sequel, Ultraman Decker. Both shows inherited the elements from Ultraman Tiga and Ultraman Dyna respectively as part of celebrating the 25th anniversary of TDG multimedia program. In addition, the list also contains characters from related media such as Ultra Galaxy Fight: The Destined Crossroad, Ultraman Regulos, and Ultraman Regulos: First Mission.

Protagonists Kengo Manaka is the 21-year-old protagonist of Ultraman Trigger: New Generation Tiga, known for being sociable and kind while bearing a sense of justice. Kengo is actually Ultraman Trigger's inner light incarnated into a human, who Reina Manaka discovered during her expedition into the petrified Ultra's ruins as an infant. He spent the remainder of his life raised in the Martian colony, taking on the job as a botanist to study the genetically-modified flower , hoping to make it bloom one day.

After receiving a nightmare regarding the dark giant and witnessing Golba's attack on the Martian settlement, Kengo merged with the eponymous Ultraman Trigger and moved to Earth, becoming the newest member of GUTS-Select. Kengo would later be banished into the past when Carmeara used her curse to revert Trigger into Trigger Dark. Through Yuzare's help, he created a time loop by convincing the dark Ultra's past iteration into defecting from his fellow members and eventually returning to the present day with gaining access to Glitter Trigger Eternity. In addition to discovering his status as the reincarnation of Trigger's inner light, Kengo swore to protect Yuna after his failure to do so with Yuzare in the past. After defeating Carmeara/Megalothor, Kengo's wish for R'lyeh to bloom came true, but he is forced to be separated from his friends in order to stabilize the Eternity Core by fusing with it. Two years later in Ultraman Trigger: Episode Z, Kengo is freed from the Core when his life started to diminish, but is later dragged into another battle against Rylar, a cult led by Zabil who stole Trigger's powers as part of becoming an Ultraman himself. After the battle, Kengo joins in the celebration with his fellow GUTS-Select members while resuming his life as both human and Ultraman once more.

Kengo eventually left the Earth and returned a decade later in Ultraman Decker, bringing along the Ultra Dual Sword when it guides him towards the titular Ultra and the new generation of GUTS-Select members. Joining forces with his successor Kanata/Decker, the two made their move to fight against the resurrected Megalothor on Earth and finally departing with Carmeara after giving the sword to Kanata.

Kengo Manaka is portrayed by .

Ultraman Ribut First appearing in Ultra Galaxy Fight: New Generation Heroes, is a member of the Galaxy Rescue Force and the protagonist of Galaxy Rescue Force Voice Drama, a mini series that chronicles his early days of participation into the elite team after events of The Absolute Conspiracy. Aside from his interactions with fellow team members, Ribut then fights against their rogue member "Daada" and eventually departed to Earth (specifically in Malaysia) to both training himself and to fight against the increasing monster attacks.

In Ultra Galaxy Fight: The Destined Crossroad, Ribut and the rest of the Ultra League reported to the Inter Galactic Defense Force after failing to stop Yullian's kidnapping. Under the Father of Ultra, he is reinstated into the latter group and supported the Ultra Force on Planet Babel, wherein Nexus' intervention convinces the young Ultra to prevent their war with the Absolutians. After his brief death and resurrection, Ribut's attempt at shielding his companions from the crossfire between Ultraman King and Tartarus on resulted with him and the two Absolutians dragged into a wormhole.

Alongside Tartarus and Diavolo, Ribut found himself in the middle of Ultraman Trigger as he once again meddled with the Absolutians' affair, while also training Kengo on how to fully control the Glitter Trigger Eternity. Upon creating a human form of his own, which he christens as , the Ultra borrowed Yuna's GUTS Sparklence and Gomora Key into his personal transformation devices to return to his original form. His Hyper Key is left to Yuna's possession after finishing his mission on Earth, which GUTS-Select would utilize to empower the Nursedessei in delivering a mercy kill to a brainwashed Darrgon.

In Ultraman Regulos: First Mission, Ribut returns from the universe of Trigger and participates in the fight against Alien Reiblood and his minions alongside Regulos, Powered, Great, and the Ultra Force.

reprises his voice role as Ultraman Ribut in Japanese, and Josh Keller in the English dub of The Destined Crossroad. His human form is portrayed by .

Marluru is a young alien who serves as the team's operator and monster informant. Aside from his appearance in Ultraman Trigger, Marluru is also one of the three main characters in Secret Origins of the Nursedessei: The Struggle of Special Section 3.

Prior to the foundation of GUTS-Select, Marluru accepted the offer to join TPU from then-staff officer Tatsumi through their common ground, and since then swore his life debt on the captain himself. Under Tatsumi's suggestion, he was initially assigned to Special Section 3 for the development of vehicles that would be used by GUTS-Select in the future. Working alongside Hotta and Terumi, Marluru's backdoor deal with Alien Wild "Zagar" becomes the key to the creation of Nursedessei, developing it alongside Akito before they would eventually be assigned to GUTS-Select. In Ultraman Chronicle D, Marluru rented an apartment at some point after Evil Trigger's destruction and is forced to share it with a freeloading Deban to his dismay. By the time GUTS-Select was disbanded, Marluru remains on Earth up to the events of Ultraman Decker, wherein he rejoins Special Section 3 in supporting the new generation of GUTS-Select members through maintenance and creation of their vehicles.

Marluru is voiced by M・A・O. The Alien Metron race first appeared in episode 8 of Ultraseven.

Deban is the navigator of , a trio of omnibus episodes within Ultraman Trigger: New Generation Tiga. In Ultraman Chronicle D, Deban freeloads into Marluru's apartment under Tatsumi's suggestion after failing to join the GUTS-Select membership, wherein he provides exposition of past Ultras while inviting past characters as guests to Marluru's house. By the end of Chronicle D, Deban took the advice of relying on his own strength to heart, deciding to forfeit his membership and leaving Marluru's house to continue his travel.

He is voiced by and first appeared in episode 21 of Ultraman Tiga.

Ultraman Regulos is an Ultra who debuted in Ultra Galaxy Fight: The Destined Crossroad, previously appearing in The Absolute Conspiracy as a silhouetted figure who was imprisoned alongside Yullian by the Absolutians. He is also set to appear as the protagonist of his own eponymous spin-off media.

Regulos was originally an amnesiac Ultra who found himself on Planet D60 after a near-death experience. He was recruited by Master Alude to join the Cosmo Beast Style and trains with his fellow students, as well as befriending the Leo Brothers from the neighboring planet. When the Alien Magma launched their attack on both planets, Regulos fail to save his fellow students from their deaths and was imprisoned by The Kingdom as part of their attempt in studying the Ultra Warriors. Due to the situation of his kidnapping, Regulos became a Parallel Isotope despite being around the same age as the Leo Brothers during the latter's active period on Earth. While recovering his strength through Yullian's help, Regulos break free from his restrains during the Ultras' intrusion into the Absolute Palace, eventually joining forces with the Leo Brothers once again to avenge Alude's death by defeating Diavolo. Following Tartarus, Diavolo and Ribut's disappearances, Regulos resumed his new life in the Galaxy Rescue Force while keeping the title of the grand master to himself in honor of Alude.

During his first arrival to Planet D60, Regulos lacked the Cosmo Beast tattoos on his arms and a pair of wrist cuffs, this "form" being designated as . As a Cosmo Beast Style practitioner, the tattoos on each of his arms that grant him the powers of and . His finishing move is the . Together with the Leo Brothers, Regulos can channel the powers of the fallen Cosmo Beast Style students and focusing their energies into the .

Ultraman Regulos is voiced by in Japanese, and by Vinay Murthy in the English dub.

Kanata Asumi is the 20-year-old protagonist of Ultraman Decker, a kind young man who originally worked at his family's rice cracker store, . When the Spheres begin their attack on Earth, Kanata is saved from certain death when he receives the from who he later learns to be his descendant Decker Asumi. Kanata becomes Ultraman Decker to fight the invaders while at the same time joining the newly reformed GUTS-Select as their newest member. As the fight progresses, Kanata learns of Decker's power coming from his future descendant of similar namesake but when given the option to retire as an Ultra, he persists and unlocks Dynamic Type, a form that is unique to Kanata himself. Near the finale of the series, Kanata gets infected by the Spheres' essence that slowly hampers his fighting skills, but manages to pull through long enough to deliver the final blow against Mother Spheresaurus and eradicating the Spheres' threats, forcing him to part ways with Ultraman Decker. In Ultraman Decker Finale: Journey to Beyond, Kanata becomes Ultraman Decker again and joins TPU's second space exploration team following Professor Gibellus' death.

Kanata Asumi transforms into Ultraman Decker with the Ultra D Flasher and a set of pertaining to Decker's forms. In addition, scanning the allows him to summon Dimension Card Monsters as Decker's limited-time supporters. At the end of his encounter with Kengo, Kanata inherited the Ultra Dual Sword and Trigger's set of cards for Decker's use in subsequent battles.

Kanata Asumi is portrayed by .

GUTS-Select is a defense team under TPU Japan branch that fights against monster attacks, with Mitsukuni establishing them using the knowledge of GUTS in mind. In the middle of its 7 years devoid of monster attacks, GUTS-Select was briefly disbanded and most of its members has since moved to Mars while Marluru remains on Earth. In addition, their combat mecha were modified into autopiloted drones when TPU begins to cut costs in Earth defenses in favor of space exploration. In Ultraman Decker, when the Spheres invade and confine Earth, GUTS-Select is reformed a year later to combat them through its list of new members while retaining most of its predecessor's assets.

Ultraman Trigger era

Yuna Shizuma