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"Let my color imbue you! R/B![1]"

―Transformation call, shared with Katsumi Minato

Isami Minato (湊 勇海イサミ Minato Isami) is one of the protagonists of Ultraman R/B and the second eldest son of the Minato Family. He is the human host of Ultraman Blu.


Isami has great respect for his brother, Katsumi, whom gave up his passion for baseball in order to support the family. Although both brothers collide with each other, they willingly cooperate with each other when fighting against opponents. Isami is a free spirited youth. Due to his clumsy attitude, he is not able to express his gratitude towards others. His desire to study space archaeology stems from the need to honor his missing mother. His devotion to scientific research makes him prefers to do things alone instead of helping his family members in the store.


Ultraman R/B

Katsumi and Isami being saved

Isami encountered Grigio Bone during his missing mother's birthday and receiving the R/B Crystals and R/B Gyro while fleeing for his life. Isami would then transform into Ultraman Blu, fighting alongside his brother Katsumi to defend Ayaka City from any monster threats. Not long after Black King's onslaught, he discovered that both his mother and Makoto Aizen used to collaborate in the research of R/B Crystals and was able to obtain the history of Ayaka City during a tour to Aizen Tech.

Although Isami's determination to help a fellow colleague resulted in acquiring Tiga Crystal, his hesitation to target Mecha Gomora while Kaoru was held as a hostage puts him in an emotional breakdown before he regained his composure.

Unknowingly to them, their battles were being watched and analyzed by Makoto himself, who presented them with several trials such as capturing an old friend within Mecha Gomora. When Makoto revealed to them his true nature and origins, the brothers fight against him directly when he transforms into Ultraman Orb Dark and they were easily defeated.

After that, Katsumi and Isami set out to do some training in the mountains so that they could beat Orb Dark. In their second training session, the brothers with some indirect help from Asahi found the Victory Crystal in a cave, granting them the power of Earth. With this new power and their training, they challenged Orb Dark to a rematch and defeated him. The brothers then took the Orb Ring NEO from Makoto.

Later, the next challenge they faced was Horoboros, who the brothers lose to despite having the Orb Ring NEO. After their defeat, Makoto reclaims the device and transforms into Orb Dark to fight Horoboros. Unable to transform, the brothers could only watch Makoto fight the beast and after his "victory", they confront him in public, telling everyone that he is behind the monster attacks but nobody believes them. Isami gets upset, so Katsumi reminds them about why they fight as Ultraman and that cheers him up. The next day, Makoto summons Bezelb to fight it as Orb Dark to further promote himself but the brothers show up and defeat the Bezelb before he could, angering him. Orb Dark tries to attack them but Horoboros reappears and evolves.

The Minato brothers defeated by Horoboros

It defeats Rosso, Blu, and Orb Dark before disappearing, but Katsumi and Isami are badly injured in the process and they detransform in from of Asahi, who finds out about their alter egos before the two of them are sent to a hospital for treatment. After they reawaken, they try desperately to hide their identities from Asahi but it is too late. Horoboros appears yet again and the two brothers transform and fight, coming up with a strategy to put it in hardened stone, but it failed. With Asahi returning the Orb Ring NEO to them, they used its power and finished off Horoboros with the Triple Origium Beam.

After that, they were faced by a vengeful Cereza, who transformed into Grigio King via Saki's Gyro. The brothers try their best but they are unable to defeat Grigio King, exhausting all of their techniques. The brothers return the next day after a short recovery period, but even with a new strategy, they were unable to defeat Grigio King until Asahi reminded them of their mother's words - that when the two of them are together, they can do anything. With that, they unlocked the power of Ultraman Ruebe, who fought Grigio King and destroyed it.

Katsumi and Isami meet Saki Mitsurugi several times, mostly while she is with Asahi and they find out that she is behind the recent monster attacks. The two of them become suspicious and further antagonize her when she announces her plan to turn Earth into a bomb to destroy Leugocyte. Later on, the brothers had their Gyros stolen by Saki Mitsurugi after King Joe attacks. Back at Quattro M, Asahi explains to the brothers about Saki's past and while Katsumi sympathizes with her, Isami is determined to stop her. Confronting Saki to get back their stolen Gyros when Gomora attacks, they also try to convince her that defeating Leugocyte at the cost of the planet is not what her brothers would have wanted, but she disagrees. The brothers fight her as Grand King Megalos and defeat her though Katsumi was hesitant to fight while Isami attacked without a doubt. After she tells them what happened to their mother, Mio, she transforms into Horoboros but like before, Katsumi hesitated in fighting her. This disagreement causes the brothers to not be able to use the power of Ruebe but after clearing their disagreements and deciding to protect what is important to them; their family, they can once again use the power of Ruebe, which they used to beat Saki but not finish her off. After chasing Saki back to a lab, the brothers and Asahi witnessed the return of Mio Minato.

Back at the Quattro M shop, Mio explained everything that happened during her time in the alternate dimension and knew that her sons became Ultramen. She even knew about the approaching Leugocyte and told her family about it. After Ruebe finishes off Kamisori Demaaga, Mio incapacitates her sons and steals their Gyros as part of a plan to stop Leugocyte. After seeing Leugocyte get turned into a R/B Crystal, Katsumi and Isami confronted their mother, saying that they would have just given her the Gyros if she had asked. She then asked the boys for help in disposing of the crystal by throwing it into the dimension they came from. Just as the boys were about to do so, Saki took back her Gyro, closing the portal and taking the Leugocyte Crystal. After leaving, Mio tells her sons not to fight because she saw the outcome while in the other dimension; which was Rosso and Blu getting destroyed by Leugocyte. Katsumi and Isami reassure their mother that they will protect the planet and run off to find Saki. They saw her at a cafe talking to Asahi and followed her when she left. Katsumi and Isami try to talk her out of detonating the planet, but they failed to persuade her. After fighting as Rosso and Blu, and then Ruebe, the brothers are defeated. After Leugocyte was set free from its imprisonment, Katsumi and Isami could only watch as the Cosmo Eater arrived.

Katsumi and Isami passed out after their defeat, but they were found by Ushio and Asahi with the former taking the R/B Gyros as well. When they reawakened, the brothers had to get Ushio to give them back their Gyros, which were taken from them as Ushio feared for their lives. They also had to deal with Asahi, who wanted to go to Saki, who was fighting Leugocyte as Grigio Regina, by herself. The brothers eventually manage to get through to them and were driven to Aizen Tech by Ushio to fight against Leugocyte. They transformed and defended Saki from Leugocyte, which reminded her of her brothers 1300 years ago.

The Minato siblings prepare to destroy Leugocyte

The next time Leugocyte launched its finisher, Grigio Regina took the hit for them and the brothers saw Saki get killed. They then charge at Leugocyte, who beats them. Just as they were about to be finished off, Mio locks their Gyros. They then saw a large portal open up above the Aizen Tech building. Rushing there, they learned of Mio's plans and confronted her, trying to convince her to stop and they were later backed up by Ushio. Jumping out the window, the brothers transform once more. The brothers fight against Leugocyte, and seeing her sons do so, Mio stopped her plans. They were nearly defeated until they were rescued by Asahi, who became the Makoto Crystal, which they used to finish off Leugocyte via the Shin Vortex Buster.

Afterward, the Minato family reflects on who and what Asahi really is and accept that she has gone. However, she comes back to them, floating down from the sky. Life goes on as usual.

Ultraman R/B The Movie: Select! The Crystal of Bond

Isami in university

One year later, Isami strives in pursuing his dreams of becoming a space archaeologist in a university and was offered a place to study abroad in California while motivating Katsumi to achieve his own dream. Isami is called by Ushio when they see Asahi talking to Riku and interrupt their conversation, but Bemstar and Gan-Q appear. Isami, Katsumi and Riku transform and fight the monsters, and save Pega in the process, who was trapped inside Bemstar and Gan-Q's linked inner dimensions. After the battle, he had dinner with Riku and Pega later on and overheard Asahi’s conversation with Riku. Isami reassured Katsumi on his dreams the following day, while finding out the way of sending back Riku and Pega to their home universe. Isami, Asahi, and Riku went searching for Katsumi when he disappeared, having gone to Hostar 21. When Snake Darkness begin wreaking havoc on Ayaka City, Isami battled it with Riku and Asahi but was easily defeated.

Isami joining his siblings and Riku during the final battle

After Katsumi returned from Planet Hostar 21, the brothers then joined forces with the former two against Snake Darkness, but were overpowered when Ultraman Tregear appeared to back up his minion. Refusing to give up, the Minato Siblings fused into Ultraman Gruebe with the Makoto Crystal’s power and rejoined Riku, who transformed into Ultimate Final once more, and eventually fight them on even terms. Finally, the siblings destroyed Snake Darkness via the Gruebing Beam and freed Yukio from the dark influence. They later say farewell to Riku and Pega, giving them gifts. Isami then parted ways with Katsumi, and reached for his own future. Ultraman R/B The Movie: Select! The Crystal of Bond

Ultraman Taiga The Movie: New Generation Climax

After sealing Grimdo, the New Generation Heroes lost their ability to transform, and went to Taiga's Earth to protect Hiroyuki Kudo. Katsumi, Isami and Riku set up a shop called Ginga Quattro Market (銀河クワトロマーケット Ginga Kuwatoro Māketto) as a front in order to blend in, and made a contract with EGIS so that they could stay close to Hiroyuki and protect him. When a gang of aliens appeared, intending to steal the Ultramen's Bracelets from Hiroyuki and escape before Grimdo arrived, Katsumi and Isami defended him from Hupnath, Lecuum, Alien Pedan, Alien Serpent, Alien Keel and Alien Shaplay using handmade replicas of their R/B Sluggers. Grimdo landed on Earth, and Hiroyuki gave the Rosso-let and Blu-let back to Katsumi and Isami respectively, restoring their R/B Gyros, and the three of them transformed and fought Grimdo. However, they were no match for the beast and were about to be defeated until Ultraman Taro arrived to rescue his son. Soon, Taro fell for Tregear's trap and was possessed by Grimdo after executing the Ultra Dynamite on it. Now under the monster's control, Taro assaulted the three Ultras and forced them to revert.


Katsumi was troubled by Taro's possession, though Isami had reassured him that everything would work out when they work together, and also told him that he found out that the flow of time in this universe was different form their home world's. After confronting Kirisaki, the New Generation Heroes transformed to fight against Tregear, Taro, and a monster army revived from their Rings. The brothers were having trouble due to Grimdo's power-ups, but their sister Ultrawoman Grigio suddenly arrived and allowed them to fuse into Ultraman Gruebe, defeating the strengthened Gorothunder. Afterwards, Tregear offered himself to Grimdo, who had been released from Taro's body. This caused Grimdo to swallow him and grow to giant size, and regain its full power. The New Generation Heroes consecutively use their finishers against Grimdo, but to no effect. Just was they were about to be blasted by Grimdo, Taro protected the New Generation Heroes with a barrier and told them to pour their energy into Taiga's Ultra Horns. Upon doing so, Hiroyuki received the New Generation Eye and transformed into Ultraman Reiga, and defeated Grimdo.

With the battle over, the New Generation Heroes gave some parting words to Hiroyuki before leaving for their home worlds. Ultraman Taiga The Movie: New Generation Climax

Transformation[Note 1]

Isami takes a R/B Crystal from the R/B Crystal Holder and flips out the middle horn of the crystal. He then inserts the crystal and the R/B Gyro opens. The Gyro is placed at chest level and the handles are pulled twice. Isami then thrusts the Gyro forward and pulls the handles one last time and places the Gyro on his chest, before transforming utilizing the elemental power of the crystal. When swapping crystals with Katsumi, instead of getting the crystal from the holder, the new crystal will appear and fall from above. The same sequence continues afterwards.

"Enshrined by Water! Azure Ocean!"

―Activation announcement for Aqua

"Enshrined by Fire! Crimson Flame!"

―Activation announcement for Flame

"Enshrined by Wind! Violet Cyclone!"

―Activation announcement for Wind

"Enshrined by Earth! Amber Terra!"

―Activation announcement for Ground

"The power of siblings become one!"

―Transformation announcement w/ Kiwami Crystal

"Enshrined by Extremity! Golden Universe!"

―Ruebe's transformation catchphrase

The sequence begins as both brothers take the Ultraman and Belial Crystals respectively, flip out the horns of the crystal and then insert the crystal as their R/B Gyro opens. The Gyros are thrust forward and the handles are pulled thrice. This causes both crystals to merge along with the Taro, Ginga, Tiga and Victory Crystals as well to form the Kiwami Crystal.

Katsumi opens the Kiwami Crystal by pressing on the side button to reveal its Kanji letter while Isami stands by his side, before placing it onto his Gyro. He then thrusts the Gyro forward and pulls the handles one last time and places the Gyro on his chest, before the two siblings transform into Ruebe. They no longer need to use the Ultraman and Belial Crystals after their first merger.

"Overlap! The Three Souls!"

―Transformation announcement w/ Makoto Crystal.

"Enshrined by Reality! Immortal Truth!"

―Gruebe's transformation catchphrase

The Minato Siblings join their hands, which summons the Makoto Crystal. Katsumi then presses the side button, opening up the crystal while Isami and Asahi stand by his side, before placing it onto his Gyro. He then thrusts the Gyro forward and pulls the handles one last time and places the Gyro on his chest, before the siblings transform into Gruebe.

Powers and Weapons

  • R/B Gyro: Isami possess this device in order to transform into Ultraman Blu.
  • R/B Crystal Holder Blu: A holder that allows Isami to store the R/B Crystals.
  • R/B Crystals: Isami uses the R/B Crystals in conjunction with the R/B Gyro in order to assume the various elemental forms of Ultraman Blu. It seems that he shares the said crystals with Katsumi.
  • R/B Slugger Blu: Isami can wield this weapon during combat against foes when fighting as Blu.
  • Makeshift R/B Slugger Blu: Isami uses a long stick weapon in combat and training when he is not transformed as Blu.
  • Vibe Spa (ヴァイブスパ Vaibu Supa): Isami's homemade Kaiju detection sensor. The device will spin if a Kaiju is detected.
  • Orb Ring NEO: Isami can use the various attacks of Orb with this item.
  • R/B Kourin: Isami wields the R/B Kourin Blu while fighting as Ruebe.

R/B Crystals in Possession

Although both siblings became separate Ultramen, they shared the same collection of R/B Crystals and thus, only a single power can be used at a time. Outside both the transformation scene and as Ultramen, Isami is suspected to hold the Type Change Crystals in his person.

Transformation Crystals
  • Ultraman Taro: Obtained simultaneously with the Gyros and R/B Crystal Holder.
  • Ultraman Ginga: Obtained simultaneously with the Gyros and R/B Crystal Holder.
  • Ultraman Tiga: Obtained after digging out the Crystal by combining Rosso and Blu's attacks.
  • Ultraman Victory: Obtained after finding it inside a mountain cave during their training.
  • Kiwami Crystal: Merged from Taro, Ginga, Tiga, Victory, Ultraman and Belial Crystals. Used to transform into Ultraman Ruebe.
  • Makoto Crystal: Summoned by the Minato Siblings. Used to transform into Ultraman Gruebe.
Auxiliary Crystals


  • His shirt bears the number 3 as a whole is referring to Earth as the third planet in the solar system. Alternatively, it also refers to his actor being a fan of Ultraman Tiga.
  • Isami was born on the 13th of April in 1999.[2] His blood type is B.


  1. The official English translation of the activation announcements are highly inconsistent: "Let's go with", "Enshrined by", "Element of", "I don".


Human Hosts and Forms
Showa Hosts Shin Hayata | Dan Moroboshi | Hideki Go | Seiji Hokuto | Yuko Minami | Kotaro Higashi | Professor Ohtani | Shuuhei Aragaki | Tetsuya Kitajima | Tadao Nambara | Takashi Ueno | Gen Otori | Choichiro Hikari | Kyoko Kodaka | Takeshi Yamato | Ryoko Hoshi | Scott Masterson | Chuck Gavin | Beth O'Brian
Heisei Hosts Jack Shindo | Dan Moroboshi (Heisei Ultraseven) | Kenichi Kai | Masaki Kazamori | Genki Kagura | Mysterious Girl | Shin Kenmochi | Agent Sean | Masato Usami | Katsuto Asahi | Daigo Madoka | Tsubasa Madoka | Amui | Shin Asuka | Gamu Takayama | Hiroya Fujimiya | Ginga Yumeboshi | Musashi Haruno | Julie | Shunichi Maki | Jun Himeya | Ren Senjyu | Nagi Saijyo | Kazuki Komon | Kaito Touma | Ikuo Hasunuma | Mirai Hibino | Kazuya Serizawa | Ryu Aihara | Shingo Sakomizu | Jin | Run | Nozomu Taiga | Hikaru Raido | Sho | Daichi Oozora | Sayuri Tachibana | Yuuto Tamaki | Gai Kurenai | Riku Asakura | Leito Igaguri | Katsumi Minato | Isami Minato | Rosso | Blu | Asahi Minato
Reiwa Hosts Hiroyuki Kudo | Haruki Natsukawa | Kengo Manaka | Ribut | Ignis | Shinji Kaminaga | Kanata Asumi
Evil Ultra Hosts Keigo Masaki | Riko Saida | Shinya Mizorogi | Hiroyuki Misawa | Mitsuhiko Ishibori | Soso | Utsuutsu | Arie Ishikari | Makoto Aizen | Kirisaki | Zabil
Other Ultraman Media Takeshi Yoshioka (Hyperspace) | Ikuru | Shin Moroboshi | Kazuma Asuka | Akiko Fuji (Ultraman F) | Shin Hayata (Marvel) | Dan Moroboshi (Marvel) | Lili Archive
Other Hosts Takeshi Hongo | Kyotaro Kagami | Officer Sakomizu | Goro Kirishima | Yuji Hayase | Tetsuo Hayase | Lily Hayase | Daisuke Misaki | Naoki Tachibana | Koh | Ai Tachibana | Zen Tachibana | Toki Goh | Naoto Sho | Takeshi Todo | Ippei Baba | Yuka Inoue | Mai Midorikawa | Sam Collins | Ai Kumashiro | Akira Kageyama | Rei | Nao | Tomoya Ichijouji | Daisuke Misaki (Glenfire) | Amate | Yuta Hibiki | Hikari Kaizaki | Chloe