The Alliance page is for exploring in-depth relationships among the players on Btooom Island, the individuals' goals, and the individuals' roles while only summarizing key events in the story for that group. For key events, the following should be included in brief and condensed details:

  • How the group was form.
  • How a member was added.
  • How a member was killed or kicked off.
  • How a leader is chosen and how that role has shifted.

MilkyCat's Rough Draft

Yoshihisa's Alliance:

Alliances (Working Title)
Active Members
Leader Yoshihisa Kira (Deceased)
Inactive Members
Inactive Member 1 Sōichi Natsume
Inactive Member 2 Kōsuke Kira
Team Status
Status Disbanded
This alliance was comprised of three individuals who were closely related to a criminal court case involving the crimes committed by Kōsuke Kira. The alliance members include: Kōsuke, the fourteen-year-old convicted criminal, himself; Sōichi Natsume, the attourney who defended Kōsuke; and Kōsuke's father, Yoshihisa Kira. Their main objective while on the island was simply to survive while searching for an alternate solution, although Yoshihisa often exhibited pessimism in any of the hopes that Sōichi placed in escaping the island safely without harm to anyone. Clearly enough, Yoshihisa is also denoted as the leader of the three, though this was mainly obtained through the intimidation of the other two. As more of their group is shown, it is even more obvious that tensions are becoming frequent within the group of three. Yoshihisa's abusive behavior toward Kōsuke was but one out of many events that occurred within the alliance, which often resulted in Sōichi defending the boy and promising him that he would protect him in the future whenever he finally stands up for himself.

Sōichi's words, however, only attributed to the fate of the alliance itself. After the three managed to secure a supply package, Yoshihisa began to hoard the supplies for himself despite Sōichi's protesting. Eventually, the two have a discussion, which ends terribly after Yoshihisa intimidates Sōichi. Kōsuke mutters an insult after witnessing the sight, to which prompts Yoshihisa to sexually abuse the boy by grabbing the boy's genitalia. Shortly after, the boy installs an implosion BIM onto Yoshihisa's shirt. Despite Yoshihisa's efforts to save himself by pulling off his shirt, he is unable to do so quickly, resulting in his death after the BIM implodes. Shortly afterward, Kōsuke revels in the fact that he killed his own father. He then asks whether Sōichi will protect him or not. To the boy's dismay, the attourney is only disgusted with Kōsuke's behavior. Shortly after, the attourney abandons the boy to his own, putting an end to both their relationship and the alliance itself.

Points of Interest:

  • Members
    • Yoshihisa Kira (Deceased)
    • Sōichi Natsume (Inactive)
    • Kōsuke Kira
  • Goal: The survival of the group in general.
  • Interactions: Tensions were high in the group itself, with Sōichi and Kōsuke often being subjected to Yoshihisa's cruelty. Although Sōichi and Kōsuke form a deeper relationship, Sōichi ultimately abandons Kōsuke after Sōichi's own words gave Kōsuke motivation toward killing his father (Yoshihisa).
  • Cause of Death(s):
    • Yoshihisa Kira was killed by his own son after many years of him abusing Kōsuke.
  • Cause of Inactiveness:
    • Sōichi Natsume abandons the group after witnessing Kōsuke killing his father (Yoshihisa).
  • Cause of Disbandment:
    • The death of Yoshihisa Kira.

Masashi's Alliance:

The appearance of this alliance exhibits the first appearance of a group of antagonists who have allied themselves with each in order to collect enough IC chips to escape the island, often with force. The members who comprise this alliance are: Masashi Miyamoto, the leader and a former war veteran;  and Sōichi Natsume, an attourney who once affiliated himself with Yoshihisa's group. Their alliance, shortly upon making their first appearance, encounters Ryōta Sakamoto. They eventually capture the man but only to have him escape moments later after stunning Sōichi with a BiriBiri 650000, though Masashi manages to track the man down to the location that houses the other members of Ryōta's Alliance (Kiyoshi Taira and Himiko at the time). Upon arriving, Masashi makes quick work of Ryōta's Alliance, managing to not only steal their supplies - including their BIM - but also wound Kiyoshi, capture Himiko, knock Ryōta off of their base into the cliffside, and assume him to be dead afterward.

Upon arriving to their base, they begin devouring the supplies and later attempt to torture Himiko. However, they're stopped short after the reappearance of Ryōta and begin to search for him. Unfortunately for both of them, they're eventually killed in the final encounter due to the combined efforts of Ryōta and Himiko.

Points of Interest:

  • Members:
    • Masashi Miyamoto (Deceased)
    • Sōichi Natsume (Deceased).
  • Goal: Collecting IC chips to escape the island, with the use of violence encouraged.
  • Interactions: Masashi and Sōichi's relationship is centered around the mutual benefit of having each as an ally, especially since allies increases the efficiency in dispatching other players.
    • Masashi's role: Masashi was not only the leader of the group but also played a core role in the alliance itself. He was not only skilled in decision-making but also showed a talent for several other areas, such as strategizing, an extensive knowledge of firearms and explosives, several forms of close-combat. His value for his allies do not stray above the mutual benefit of having them in the first place, as he shows no empathy for decisions that would endanger them.
    • Sōichi's role: Sōichi often, at times, heavily relied on Masashi's judgment and his areas of expertise to assist in both decision-making and dispatching other players. His role is to be considered the opposite of Masashi's for several reasons. For one, he is unskilled in many areas suited for survival, providing little to bring to an alliance. As for two, his inability to think more for himself and to question the motives of Masashi led him to spiral down into the degradation of his mentality as a result of the stimulants received from Masashi himself; eventually, this would attribute toward his death. However unbeneficial he may be to an alliance, his nature fit perfectly into Masashi's plans as Masashi was able to ally himself with a person who was obedient enough to become an extension of his will.
  • Cause of Death(s):
    • Sōichi was killed by Ryōta with a cracker BIM.
    • Masashi was heavily wounded and disfigured by Himiko with a blazing gas BIM but was eventually killed by Ryōta with a timer BIM.
  • Cause of Disbandment:
    • The deaths of both members.

Himiko's Alliance:

Nobutaka's Alliance:


(Note: This includes members that make up almost all of the known alliances, temporary and permanent, deceased and alive. Also, not every member of an alliance has been identified on this site.)

  • Ryōta's Alliance:
    • Ryōta Sakamoto (Inactive)
    • Kiyoshi Taira (Deceased)
    • Himiko (Missing/Inactive)
    • Shiki Murasaki (Deceased)
    • Masahito Date (Deceased)
    • Kōsuke Kira (Temporary)
    • Hidemi Kinoshita (Deceased)
    • Nobutaka Oda (Missing/Inactive)
  • Yoshihisa's Alliance:
    • Yoshihisa Kira (Deceased)
    • Sōichi Natsume (Inactive)
    • Kōsuke Kira (Inactive)
  • Masashi's Alliance:
    • Masashi Miyamoto (Deceased)
    • Sōichi Natsume (Deceased)
  • Himiko's Alliance:
    • Himiko (Inactive)
    • Isamu Kondō (Deceased)
    • Masashi Miyamoto (Inactive)
    • Mitsuo Akechi (Deceased)
  • The Unidentified Man's Alliance
    • Unidentified Man A (Deceased)
    • Hidemi Kinoshita (Inactive)
  • Nobutaka Oda's Alliance:
    • Nobutaka Oda (Inactive)
    • Hidemi Kinoshita (Inactive)
  • Kōsuke's Alliance:
    • Kōsuke Kira (Inactive)
    • Tomoaki Iwakura (Deceased)

Taka's Rough Draft

Ryōta's Alliance

Alliances (Working Title)
Active Members
Leader Ryōta
Member 2 Himiko
Inactive Members
Inactive Member 1 Taira (Killed)
Inactive Member 2 Hidemi Kinoshita (Killed)
Inactive Member 3 Shiki Murasaki (Killed)
Team Status
Status Active

Masayoshi's Alliance

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