The Culling Game is the most unprecedented act of jujutsu terrorism ever set into motion. The conflict picks up immediately after the events of the Shibuya Incident and is masterminded by Kenjaku with the aim of evolving mankind through the optimization of cursed energy. The game is a deadly battle royale where players kill each other using jujutsu. Throughout the game, players must follow the strict rules of the game and fight across ten barrier colonies lined up in a line down Japan.
Prologue
Kenjaku believes that there has to be more potential in cursed energy in terms of humans than there is in jujutsu sorcerers and cursed spirits. His first attempt at doing something more was the Cursed Womb: Death Paintings. This only taught Kenjaku that something of his making cannot surpass his own potential. Thus, he had to create such a degree of chaos that an answer would be clouded in darkness.
Using Cursed Spirit Manipulation to extract Mahito’s cursed technique, Kenjaku could cast Idle Transfiguration remotely and activate two types of non-sorcerers that he marked. The first are people who ingested cursed objects, like Yuji Itadori. The second are people with brains that were supposed to be nonsorcerers but had obtained cursed techniques, like Junpei Yoshino. Both had their brains adjusted for jujutsu and received strength: the former as vessels for sorcerers from past eras and the latter with the capacity to use cursed techniques as new sorcerers for the modern era.
Kenjaku also releases the seal on all the cursed objects he got the vessels to consume. Some of the people marked have been in a deep sleep ever since they came into contact with his cursed energy, but they will soon awaken.
These cursed objects are remnants of sorcerers that Kenjaku contracted with over a thousand years ago. However, all of those Binding Vows became null when Kenjaku took Suguru Geto’s body. Kenjaku intends to let hundreds of sorcerers fight each other in order to deepen their understanding of cursed energy. He believes it will be just like the Heian Era, the golden age of jujutsu.
While fleeing Shibuya, Kenjaku set loose countless cursed spirits throughout Tokyo; creating a chain reaction from the Shibuya Incident that sent over ten million curses affecting the twenty-three wards. Megumi Fushiguro finds out about his sister’s connection to the whole incident and reveals to Yuji Itadori that his sister has been caught up in Kenjaku’s Culling Game among jujutsu sorcerers. Megumi finds his way to gather his allies and contacts Master Tengen with the hope of finding out more about this Culling Game and what Kenjaku aims to achieve.
About the Culling Game
Master Tengen explains that Kenjaku couldn’t use their barrier to turn everyone in Japan into sorcerers using Idle Transfiguration because he lacks the cursed energy. The process would be utterly inefficient and therefore has led Kenjaku to decide on evolving humanity by merging them with Master Tengen.
The world itself is the evolved soul of Master Tengen and merging with them would create beings that are greater than a sorcerer. But they would be new beings that are both “there and not there”, where no boundaries exist between people. Not unlike what befell Tokyo, evil would spread and the impurity of a million people would overflow the entire world, not only Japan.
According to Master Tengen, the Culling Game utilizes the cursed energy of the players and the barriers for a ritual that prepares the humans of Japan for the merger. With such a ritual, Master Tengen would be forced to merge with the humans of Japan and “convey them to the other side”. In order to conduct this type of ritual, Kenjaku has taken certain binding vows, one of which is that he is not the game master. This goes against Megumi’s group because killing Kenjaku will not end the game. The Culling will continue until all of its players are dead and its rules ensure that no one can interrupt the ritual.
There were ten colonies in Japan that were connected by boundary-binding barriers forming a line along the archipelago. This does not include Hokkaido due to a Jujutsu Society created barrier and its sacred territory status. Every single human presently in Japan has been cursed in preparation for the merging ritual.
There is no rule regarding the entry and exit of the colonies and right from the onset, the players will receive the goal of exiting the barriers as a way of encouraging competition. For the barrier to enclose every participant, they will be strengthened with the belief that the participants entered of their own free will. Very little is known about the game master, but the shikigami named Kogane acts as the game interface. All players are under strict rules, but Kenjaku won’t be shown any bias.
Rules

Original Rule
1. After awakening a cursed technique, players must declare their participation in the culling game at a colony of their choice within 19 days.
The players were awakened by Kenjaku around midnight on October 31st. This means players such as Tsumiki Fushiguro get until approximately November 19th to declare their participation.
2. Any player who breaks the previous rule shall be subjected to cursed technique removal.
Cursed Technique Removal is some sort of mysterious process which doesn’t include Idle Transfiguration. Shoko Ieiri theorizes that it somehow affects the player’s brain and would kill the player, or else all the players can just refuse to participate. Master Tengen confirms it would have resulted in the player’s death.
Players without cursed techniques aren’t at risk from this rule.
3. Non-players who enter a colony become players at the moment of entry and shall be considered to have declared participation in the culling game.
Civilians within a barrier at the start of the game shall be given at least one opportunity to safely leave.
4. Players score points by ending the lives of other players.
5. Points are determined by the game master and indicate the value of a player’s life. As a general rule, sorcerers are worth 5 points and nonsorcerers are worth 1 point.
Cursed spirit participants are worth 5 points as well.
6. Players may expend 100 points to negotiate with the game master to add one new rule to the culling game. However, players cannot add their own life’s value to the amount that can be spent.
Rules cannot be subtracted.
7. In accordance with the previous rule, the game master must accept any proposed new rule unless it will have a marked and long-lasting effect on the culling game.
8. If a player’s score remains the same for 19 days, that player shall be subjected to cursed technique removal.
Player Additions
9. Players shall have access to the following information about other players – name, points, number of rules added and current colony. (Added by: Hajime Kashimo)
10. Players may transfer a number of points of their choosing to another player. (Added by: Hiromi Higuruma)
11. A player can leave the game by expending 100 points to invite a new player into the colony as a substitute. (Added by: Megumi Fushiguro)
12. Players may enter and exit across colony borders. (Added by: Yorozu)
13. As of this moment – 9:09 P.M. on November 18, 2018 – no new players may join the Culling Game. (Added by: Kenjaku)
14. The Game will end upon the deaths of all players except Suguru Geto, Megumi Fushiguro, and Shiori Himi. (Added by: Kenjaku)
15. Megumi Fushiguro has the authority to activate the merger of humankind with Tengen. (Added by: Kenjaku’s failsafe)
Barrier Rules
There are rules that seem to go unaddressed in the Culling Game due to the barriers.
When players respond to Kogane’s message when they enter a colony, they are transferred to one of nine pre-established locations at random. This process keeps players from entering into the game together through separation, but it also catalyzes a secondary awakening within new players.
The rules of the Culling Game are such that it does not prevent players or communications from leaving the colony. This is a consequence of the barrier, much like how curtains were deployed during the Shibuya Incident. The Jujutsu High students had feared that the barriers would still remain unbreachable even if they added a rule to move across them. In the end, however, it proved not to be the case, as shown when Yorozu’s rule allowed players to go in and out of colony barriers.
Final Plan
Megumi thinks that to resolve the issue, Satoru Gojo needs to be freed from Prison Realm. However, to do that, they require support from a player known as Angel. She is a sorcerer who lived a thousand years ago and possesses the power to nullify cursed techniques. Her cursed technique can effectively release Gojo using the back of Prison Realm, which is with Tengen.
Megumi and his team devised a strategy to overcome the Culling Game and rescue his sister with the help of information provided by Master Tengen. The rules of the game cannot be subtracted, but they can be negated by players in an indirect manner by incorporating additional rules. Yuta Okkotsu enters Sendai Colony in Miyagi without delay to collect information regarding the game.
At the same time, Yuji along with Megumi, finds Kinji Hakari and Panda to ally with them. Hakari agrees to make a deal with them, as all four are present for an announcement about another rule for the game, which has been added by Hajime Kashimo. This rule gives players more information about each other. After this, Kogane introduces itself to Yuji Itadori as his personal liaison for the game. Yujii is already being counted as one of the players, even though he does not belong to a colony or either type of player that Kenjaku awakened. Yuji figures this is probably because of his connection to Sukuna.
Megumi takes out Yuji’s Kogane to read through a list of players made available by this rule. He looks for a player with at least a hundred points who does not want to add rules. By pressuring that player to add a rule to let Tsumiki escape from the Culling Game, the students will be able to avoid killing people.
The first rule that they have to balance is rule number eight, whereby players will be subjected to curse technique removal if their score remains the same for nineteen days. They can balance this rule by adding another rule that allows players to transfer points for free. Megumi proposes adding another rule that players can spend points to leave the game. Hakari thinks that it will not work because it will conflict with the lasting effect in the game. Megumi agrees but thinks that it could work if it substitutes a non-player into the game.
The course of action is to search for the Angel to break the seal of Prison Realm. Meanwhile, they would also track down Hajime Kashimo and Hiromi Higuruma to compel them to add favorable rules in the game. Kogane, however, has nothing recorded in his files about the Angel, other than she might be found in eastern Tokyo.
However, Hakari intends to go with Panda to Tokyo No. 2 Colony to challenge Hajime Kashimo. Yuta hasn’t been in contact with anyone since entering the barriers, which means that they block cell phone reception. Hakari asks Kirara Hoshi to stay outside the barriers in order to monitor the situation. Yuji and Megumi will go to the Tokyo No. 1 Colony in search of Hiromi Higuruma, another player with one hundred points.
On November 12th at noon in Tokyo, Yuji, Megumi, Hakari and Panda officially declare their participation in the Culling Game and enter their respective colonies.