Masashi Miyamoto
Masashi Miyamoto
Vital Statistics
Name Masashi Miyamoto
Kanji 宮本 雅志
Gender Male
Age 38
Height 184 cm
Blood Type A
Professional Statistics
Occupation Officer at the
Defense Force (former)
Military writer
Hometown Tokyo
Btooom! Statistics
Status Deceased
BIM Type Cracker
Kill(s) 1
Japanese VA Takaya Kuroda
English VA Jovan Jackson
Image gallery

"If you ask me, the people playing the game are the sane ones." — Masashi Miyamoto

Masashi Miyamoto (宮本 雅志 Miyamoto Masashi) was a player in the real-life Btooom! game. He was originally a member of a group comprised of Himiko, Isamu Kondō, and Mitsuo Akechi, however, tensions led Masashi to kill Isamu, and thus created a falling-out with the remaining members. Once on his own, Masashi later formed his own group with Sōichi Natsume and served as a major antagonist toward Ryōta Sakamoto's group.


Masashi is a tall, extremely muscular man. His face sports very rough features, such as his dark-tinted, sunken eyes. His hair is black and shriveled and extends down to his nape. His hair is kept in a forest camouflage-patterned bandana. (In the anime, however, his bandana is red.)

Aside from his bandana, his attire consists of a black, sleeveless shirt and dark green cargo pants. He is sometimes seen wearing a dark-green, unfastened military coat, with rolled-up sleeves at his elbows. According to Masashi, his coat is made out of a special type of resin, which resists electroshock weaponry, and also symbolizes his membership in the French Foreign Legion. His accessories consist of two dark-green sweatbands, one worn on each wrist, and a necklace of the cross of Christianity. He wears camouflage-patterned combat boots. He carries a combat knife, which he makes use of in battles. In several scenes, he is seen smoking a cigarette.

As a Btooom! participant, Masashi possessed a bandolier and had an IC chip implanted in his left hand. However, his bandolier was stolen from him early on and wasn't recovered until much later. After recovering his bandolier, he is seen wearing four bandoliers - three that were stolen from Ryōta's group - in a cross-shaped fashion, with several types of BIM attached.

During his final encounter with Himiko and Ryōta, he became severely disfigured from a blazing gas BIM activated by Himiko.


When faced with others, Masashi is rather scornful toward them, especially toward their idealistic notions. He is short-tempered and also quick to resort to violence. He justifies his behavior solely on the concept of the survival of the fittest, however, his sadistic nature often overshadows such justifications. He follows a pragmatic approach and holds an unwavering disapproval of idealistic notions. Whenever in a group, he will either take a commanding role or conflict with the group's leadership. Regardless of whether he is leader or not, he is extremely proactive. His decision-making skills often has others rely on his judgment. His strategies follow a simple approach hardened by his military experience, though he neglects the safety of his allies, seeing them as dispensable.

As a result of his military experience, he specializes in various forms of warfare, weaponry, and torture. He is prideful of such skills and occasionally utilizes them in various situations; however, his overreliance of such skills has him overlook the strategic importance of utilizing both the BIMs and the radar.


According to Masashi, he had been an officer of the Japanese Special Defense Force (JSDF), had undergone special army ranger training, and had been a member of the French Foreign Legion. It is through these experiences that he has become specialized in several areas of expertise.


On the morning of the first day, Masashi, along with Isamu and Mitsuo, encounter a sleeping Himiko. Himiko eventually joins their group. Shortly after, Masashi, along with Mitsuo, bring back fish they've obtained by using Masashi's cracker BIM. While they're eating, Masashi notes that escape is improbable, given how isolated the island is, and that they may have to kill in order to survive. However, Isamu objects, demanding that they focus on the group's well-being instead. Irritated, Masashi insults Isamu. The argument then escalates drastically when Masashi produces a cracker BIM, which has Isamu respond by reaching for his own. In order to show how powerless Isamu is, Masashi takes Himiko hostage, mocking him. Unexpectedly, Himiko produces a taser and attempts to stun Masashi. Masashi quickly lets her go. Shortly after, Mitsuo argues that they remove their weaponry in order to avoid conflicts. He then proposes the idea of electing a leader to watch over their weapons. The group then agree to have Himiko act as leader.[1]

At noon, Masashi, along with Himiko and Mitsuo, investigate the location of a parachuted supply case. After obtaining the supply case, they proceed to open it, discovering various items inside, including food and water. They then begin to consume the food and water. However, upon Isamu's appearance, their actions are quickly opposed by him. As Isamu explains the importance of rationing, Masashi slits Isamu's throat with his combat knife from behind. Isamu later succumbs to his wound. Soon after, Isamu's IC chip is possessed by Masashi. [2]

On the morning of the second day, the group's BIMs and supply case are found missing, along with Himiko and Mitsuo, prompting Masashi to pursue the two. Upon reaching a nearby bridge, Masashi confronts the two and learns about the existence of the radar from Mitsuo. Masashi then attempts to advance, however, after Mitsuo hurls a blazing gas BIM in his direction, he retreats. Whilst eluding the gas, Masashi notes the BIM's lethality and decides to track them later. [3]

On the morning of the third day, Masashi kills a komodo dragon with his combat knife. Now teamed with Sōichi, their group sends out a sonar wave, which reacts to Himiko's IC chip. Shortly after Ryōta arrives to investigate, Masashi attacks him with his combat knife, though he misses due to Ryōta sensing his attack through a sonar wave. Once Ryōta retreats, Masashi gives chase. Shortly after, Ryōta manages to produce a cracker BIM and threaten Masashi. Ryōta then proceeds to negotiate with Masashi, telling him that Tyrannos Japan is responsible for their situation and of his plan to collect information and escape afterward. However, negotiations fail after Masashi notes there is no clear method in his plan. Frustrated, Ryōta leaves. However, he is stopped short after Sōichi casts a timer BIM in his direction. After Ryōta dodges the explosion, Masashi strikes Ryōta with the butt of his combat knife, incapacitating him momentarily. Sōichi proceeds to discuss Ryōta's fate with Masashi, though this ends shortly when Ryōta stuns Sōichi with Himiko's taser. After Ryōta escapes, Sōichi apologizes to Masashi. However, Masashi isn't angered by this event. Masashi tells Sōichi he had planned to let the man go in order to have him lead them to Ryōta's allies. The two then proceed to track down Ryōta.

Once at Ryōta's group's base, Masashi reappears to confront Ryōta, Himiko, and Kiyoshi Taira, with his combat knife. Once there, he briefly tells the group of his past and why he was able to easily track Ryōta. As Masashi studies his surroundings, he notes that Himiko still possesses both the BIMs and the supply case she took from him. After noting Mitsuo's absence, he questions Himiko on whether she killed Mitsuo or not. Ryōta, however, armed with Himiko's taser, protests, reassuring that Tyrannos Japan must've left holes that they could exploit. None of this is taken seriously by Masashi, however. As Masashi advances toward Ryōta, Masashi notes that due to his military coat having been made from a special resin the taser's effectiveness would be reduced. Suddenly, Kiyoshi attempts to restrain Masashi from behind, telling Ryōta to stun Masashi. However, Masashi flips Kiyoshi onto the ground and severs the man's left fingers, save for his thumb. Masashi then attempts to crush Kiyoshi's severed fingers. Provoked, Ryōta rushes Masashi with Himiko's taser, prompting Masashi to kick Ryōta off the cliff. Once Masashi approaches the edge, he remarks of the difficulty in retrieving Ryōta's IC chip. Himiko then takes the opportunity to make her escape, however, she is captured by Sōichi. Shortly after, Kiyoshi threatens Masashi with his homing BIM, demanding Himiko's release. Masashi simply replies that he'll wait for him to die in order to safely retrieve his BIM. Masashi then leaves with both Ryōta's BIMs and the group's supply case.

Once at their base, Masashi and Sōichi begin consuming the food and water. Himiko, however, protests. Irritated, Masashi begins to torture Himiko with his combat knife, though he is interrupted shortly by a sonar wave sent from an unknown person. After having their location revealed, Masashi calls for a retreat. However, when Himiko and the unknown person exchange two sonar waves, Masashi realizes Ryōta is alive. Masashi, now equipped with Ryōta and Himiko's BIM, devises a pincer movement as their strategy. Before they do, Masashi, at Sōichi's request, supplies Sōichi with stimulants in order to repress the man's fear. Masashi then advises Sōichi to set his timer BIMs to three seconds.

As Masashi moves into position, he senses a sonar wave from Ryōta and notes that he is heading toward Sōichi's direction. Soon after, an explosion is heard, which Masashi assumes to be from Sōichi's BIM. However, a sonar wave is unexpectedly sent, which reveals a person heading toward Masashi's position. After the same person sends another sonar wave, Masashi concludes from the lack of explosions that Sōichi had been killed. He then positions himself closer in order to lay an ambush. Once in range, Masashi ambushes him. However, the person is revealed to be Sōichi himself. Surprised, Masashi demands to know the situation. Sōichi replies that Ryōta vanished after his BIM's explosion. Masashi, along with Sōichi, then send out several sonar waves to search for Ryōta, unwittingly countervailing each other's sonar waves. Several moments later, they locate Ryōta with Himiko. Masashi, after realizing that Ryōta neutralized his booby trap, devises another pincer movement.

Moments after Sōichi's death, Masashi reappears, holding Himiko hostage. He then proceeds to taunt Ryōta, telling him to settle this physically without any weapons. He then discards his combat knife before turning a corner. Ryōta then rushes out of hiding and obtains the combat knife. However, Masashi, expecting such actions, attacks him, and eventually restrains him. As he attempts to break Ryōta's right arm, he is interrupted when Himiko jumps onto Masashi from behind. After throwing Himiko off, he realizes that she had activated a blazing gas BIM on Masashi's bandolier. While Ryōta and Himiko escape, Masashi attempts to discard the activated BIM, however, it triggers.

Unexpectedly, Masashi survives, though he is horribly disfigured. He pursues both Ryōta and Himiko, surprising them when he grabs Himiko's leg as Ryōta lifts her to safety. Ryōta drops a timer from above, prompting Masashi to rush over to the BIM in order to toss it back. He, however, after seeing that the BIM was counting down from three, realizes that it was one of Sōichi's BIMs. After realizing it is now too late, he is killed instantly.

Equipment and Skills

Combat Knife

  • Masashi's primary weapon.
  • Ryōta obtained Masashi's combat knife during their battle, though he was later disarmed of it by Masashi. After Masashi's death, Ryōta obtains his combat knife again.


Cracker BIM

  • Masashi rarely used his BIM in combat, preferring to use his combat knife instead. He only used his BIM to fish and to set up a booby trap wedged in the top of a doorway that triggered when a person opened the door, resulting in the cracker dropping from the doorway.[4]
  • Observed amount used: 2.
  • He used his BIM to fish during his time with Himiko's group on the first day. The other time was when he prepared a booby trap during his third encounter with Ryōta on the third day.
  • These BIMs were stolen from him by Himiko but were later recovered from her. They were obtained by both Ryōta and Himiko after Masashi's death.

Timer BIM

  • Ownership not possessed.
  • These were stolen from both Ryōta and Himiko. Both later recovered their own BIM.

Blazing Gas BIM

  • Ownership not possessed.
  • These were stolen from Himiko. Himiko later recovered them.

Implosion BIM

  • Ownership not possessed.
  • These were stolen from Ryōta. Ryōta later recovered them.

Physical capabilities

Due to Masashi's muscular built, he is capable of handling more strenuous tasks than the average person is. As a result of his military experience, he specializes in both hand-to-hand combat.

Intellectual capabilities

Due to his military experience, Masashi is capable of adapting to his situation mentally. He possesses a significant amount of knowledge in weaponry, giving him an advantage over his foes when it comes to using BIMs. It is also mentioned that he is able to torture a victim while keeping them alive as much as possible.

Masashi is also skilled in deduction, which has allowed him to comprehend the mentality of his opponent to some extent, and, at times, manipulate them. During battle, he has been shown to strategize with the placement of both himself and his ally by creating opportunities for pincer movements and by using choke points in order to effectively dispatch his foes. He has also proven himself to be an expert at both tracking and navigation, making any attempts to elude him difficult.


  • Masashi Miyamoto is the first of several characters that we eventually see naming and counting the IC chips that they plan to collect in order to complete the required set of eight,[5] although he makes some wrong assumptions.

He plans to collect the chips from Ryōta Sakamoto, Himiko, Kiyoshi Taira and of his own recently killed ally Sōichi Natsume, adding them to his own, to Mitsuo Akechi's (which he assumes to be with Himiko), to Isamu Kondō's (which he acquired early on by killing him) and to the two chips that he assumes Ryōta to have acquired previously (namely Yoshiaki Imagawa's and Yoshihisa Kira's), for a total of nine that exceeds the eight required to leave the Island.

In reality Mitsuo Akechi's and Yoshihisa Kira's IC chips are both with Kiyoshi Taira at this point,[6][7][8] while Yoshiaki Imagawa's has been collectd by someone else, perhaps Nobutaka Oda.[9][10]


  1. Btooom! episode 2
  2. Btooom! episode 2
  3. Btooom! episode 2
  4. Btooom! chapter 28, page 17-19
  5. Btooom! chapter 30, page 6
  6. Btooom! chapter 11, page 3
  7. Btooom! chapter 14, page 3
  8. Btooom! chapter 47, page 17
  9. Btooom! chapter 47, page 11
  10. Btooom! chapter 47, page 20-24
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