Journey to Extinction

📏 Size and Behavior Size: They are relatively small, roughly the size of a human head or a volleyball. They usually float at shoulder height or above the head of the sorcerer to whom they are assigned.

Appearance: They are not always physically visible. Kogane usually materialize out of nowhere when the player summons them, when there is a rule update, or when a player scores points after a death.

💻 Video Game Visual Interface Despite their organic appearance, they literally function like the menu of a macabre video game. When a sorcerer needs information, the Kogane positions itself in front of them and projects flat holographic screens into the air. These screens display text with the player's name, their current point total, and the rules of Journey to Extinction.

The Kogane are shikigami (summoned spirits) that function as referees, guides, and personal interface systems for each player during the Journey to Extinction (Culling Game). Visually, its design is a disturbing mix between a giant insect and a cybernetic or demonic element. Its appearance and physical characteristics are detailed below:

🪲 Insect Base Form: The overall appearance of the Kogane is heavily inspired by a beetle (in Japanese, the word kogane usually refers to golden beetles or May beetles).

Shell: They possess a hard, rounded and segmented exoskeleton that covers their body, giving them an almost armored or metallic appearance.

Wings and Flight: On their backs they have transparent membranous wings (like those of a fly or beetle in flight) that they beat at high speed. This allows them to levitate and constantly flutter beside their player as if they were a personal surveillance drone.

Limbs: They have six thin, pointed, jointed legs, typical of arthropods, which normally hang downwards while floating.

👄 The Grotesque Face (The Uncanny Valley): What makes the Kogane visually disturbing and removes any aspect of a "harmless pet" is its face. Instead of having a normal insect head with mandibles, the front of its face features an exceptionally wide mouth with thick, square teeth, very similar to human teeth. This mouth is usually curled into a creepy, perpetual smile. They lack conventional visible eyes, reinforcing the sense that they are blind, unempathetic tools, programmed solely to manage the game of death.

📜 The Main Rules and the Kogane The game is overseen by Kogane, small flying shikigami (resembling metallic insects) assigned to each player. Kogane acts as referee, system interface, and rule enforcer. The game began with eight unbreakable rules. The most important ones dictate the life and death of the participants:

Rule Description: Time Limit: Awakened players had to declare their participation in a colony within 19 days of their awakening.

Score for Killing: Killing another sorcerer grants 5 points. Killing a non-sorcerer grants 1 point.

Technique Deprivation: If a player does not change their score (neither kills nor gains points) for 19 days, their cursed technique is removed. In the world of Jujutsu, removing a sorcerer's technique by a Binding Vow almost always results in their brain death.

Rule Creation: If a player accumulates 100 points, they can spend them to add a new rule to the game. Kogane must accept the rule as long as it does not contradict the existence and continuity of the game itself.

♟️ The Players To ensure the game had enough violence and energy, Kenjaku spent centuries preparing three main types of participants:

Reincarnated Sorcerers (from the past): Sorcerers from ancient eras (such as the Heian or Edo periods) with whom Kenjaku made Binding Vows. They were given modern bodies (vessels) so they could revive and fight. Examples: Hajime Kashimo, Ryu Ishigori, Uro Takako.

Awakened Humans (present day): Ordinary people previously marked by Kenjaku. Using Mahito's Inactive Manipulation technique, he altered their brains to grant them the ability to use cursed energy and innate techniques overnight. Examples: Hiromi Higuruma, Fumihiko Takaba.

Voluntary Invaders: Modern-day sorcerers who willingly entered the game to stop it. Here are the protagonists: Yuji Itadori, Megumi Fushiguro, Yuta Okkotsu, Maki Zenin, and Hakari Kinji.

It is a macabre battle royale or nationwide survival tournament orchestrated by Kenjaku. It is not a simple game for fun; it is a massive ritual driven by Binding Vows (cursed contracts) with strict and lethal rules. The following explains how this event works and why it was created:

🎯 The True Purpose As mentioned in his master plan, Kenjaku's goal is to merge Master Tengen with the population of Japan to force human evolution. However, an event of that magnitude requires an astronomical amount of cursed energy.

The Journey to Extinction was specifically designed to collect that energy. By forcing hundreds of sorcerers to kill each other within designated barriers, the cursed energy released by their deaths and combat is accumulated and transmitted across the country to prepare for the assimilation ritual.

🗺️ Colonies and Structure: Kenjaku established 10 colonies in different regions of Japan (such as Tokyo, Sendai, Sakurajima, etc.). Each colony is surrounded by an immense barrier.

These colonies are connected to each other, forming a line that crosses the country. As the "game" progresses, the cursed energy flows from one colony to another to "purify" the humans on the other side of the barriers and prepare them for the merge. Any ordinary civilian who was already inside a colony at the time the barrier was created had at least a chance of getting out unharmed, leaving inside only the willing participants or those trapped later.

🧙‍♂️ Jujutsu Sorcerers: Jujutsu Sorcerers are rare humans who possess two main characteristics: They can see the cursed energy and the cursed spirits. They can control the flow of their cursed energy, preventing it from leaking out of their bodies, and using it at will to fight curses.

🧬 Advanced Concepts The use of cursed energy is not limited to simply striking. It has extremely complex applications:

Reverse Curse Technique (RCT): By default, curse energy is negative and therefore destructive. However, some genius sorcerers can multiply negative energy by negative energy (- times - = +) to create positive energy. This positive energy is primarily used to heal severe physical wounds or regenerate limbs.

Black Flash: This phenomenon occurs when a sorcerer applies cursed energy to a physical strike with a margin of error of 0.000001 seconds. The impact creates a spatial distortion, the energy flashes black, and the destructive power of the strike increases to the power of 2.5.

Binding Vows: These are invisible contracts made with cursed energy. A sorcerer can impose a restriction on themselves (for example, explaining aloud how their power works) in exchange for increasing the effectiveness and strength of their attack.

It is the fundamental power system and the energy source that drives all the supernatural abilities in the series. The following explains its foundations, how it works, and its key concepts:

🌑 Origin and Nature: The cursed energy originates from the negative emotions of human beings. Feelings such as fear, hatred, anger, resentment, jealousy, and sadness generate this energy.

Since all human beings experience negative emotions, almost all of humanity naturally produces cursed energy, although the vast majority are unaware of it.

💧 The "Escape" and the Cursed Spirits Normal people (not sorcerers) cannot control their emotions to a level that allows them to retain this energy, so they constantly "filter" or "leak" it outwards.

When this filtered cursed energy accumulates in places where many negative emotions converge (such as schools, hospitals, or cemeteries), it eventually takes shape and comes to life, creating Cursed Spirits (or simply "curses").

Curses are invisible monsters to normal people and are made purely of cursed energy.

⚡ The Electricity Analogy: In the series, Satoru Gojo explains cursed energy using a very precise analogy: The Cursed Energy is like electricity: It is pure, volatile power. It can be used on its own to strengthen the physical body, strike harder, or protect oneself from attacks (like an invisible shield).

Cursed Techniques are like household appliances: To achieve specific effects (such as summoning fire, manipulating shadows, or changing bodies), "electricity" (cursed energy) must be channeled through an "appliance" (each sorcerer's innate technique).

A Binding Vow (also translated as Binding Pact or Shibari in Japanese) is an unbreakable contract forged with cursed energy. It works under the fundamental principle of equivalent exchange: by imposing restrictions, risks, or sacrifices on oneself, a sorcerer can obtain in return a significant increase in power, efficiency, or skills. Binding Vows are one of the most powerful and strict mechanics in the jujutsu power system, and are divided into two main categories:

👤 1. Binding Vows with Oneself These are restrictions a sorcerer imposes upon himself. Since the contract is only with his own cursed energy, the consequences of breaking it are not fatal.

Consequence of breaking it: If the sorcerer stops following his own rule, he simply loses the extra power or benefit he had gained, returning to his normal state.

Classic examples: Revealing the Cards (Revealing the Technique): This is the most common binding vow. If a sorcerer willingly explains to their opponent how their cursed technique works (giving the enemy an advantage), their technique becomes significantly stronger and more effective.

🤝 2. Binding Votes with Others These are pacts made between two or more people. They are extremely dangerous and absolute. Both sides must agree to the terms, and the malevolent energy acts as the "judge" that guarantees their fulfillment.

Consequences of breaking it: The consequences of breaking a pact with another person are unpredictable and catastrophic. No one knows exactly what will happen, but the penalties can range from losing all cursed energy to absolute death and spiritual ruin. For this reason, no one dares to break them intentionally.