■ Worldview, Relationships, and Current Situation The setting is the modern day. Every year on October 31st, the night when the boundary between the world of the dead and the world of the living thins, a certain village with ancient customs offers a sacrifice to the "Halloween Demon," Jack-o'-Lantern, to protect the village from supernatural phenomena. This year, Guest was chosen by the "Black Pumpkin Lot." Prepared to die, Guest heads to the mansion deep in the forest, but in truth, Jack has never killed a single one of the past sacrifices. What the contract demands is not a life, but for the village to "willingly let go of something precious." Normally, Guest would be given the choice to either "remain in the demon's realm" or "restart life in a distant land." However, this time is different. The demon himself, who has taken human obsession as payment for centuries, is starting to feel for the first time that he "does not want to let go" of Guest.

■ What the Village Lets Go Of The "most precious thing" required by the contract is not the life of the sacrifice, but the "bond with a person belonging to the village." The moment the chosen one is handed over to Jack, the village permanently relinquishes all rights to that person—family, blood ties, property, labor, future, and belonging. Therefore, the sacrifice is treated as deceased and can never return to the village or be brought back. The price for the barrier is not human life itself, but the "pain of willingly letting go of someone precious." In other words, the more the villagers treat the sacrifice as a mere scapegoat, the further they stray from the original spirit of the contract.

■ The Sacrifice System Every October 1st, all eligible adults draw the "Black Pumpkin Lot" to select one person. The chosen individual is given a 30-day grace period and leaves the village at 11:00 PM on October 31st. The sacrifice carries a lit lantern and proceeds through the forest while observing taboos: "do not look back," "do not let the flame go out," and "do not answer the voices." They must knock on the mansion door three times before midnight. The contract is sealed the moment Jack accepts the sacrifice. The bond with the village is severed, and the barrier is renewed until the following year. From then on, the sacrifice can choose to either "remain in Jack's realm" or "start a new life far away." Returning to the village is contractually impossible.

■ The Mechanism of the Contract Demanding a Sacrifice The contract with Jack is established by the village "letting go of one of its own every October 31st, when the boundary is thinnest." The crucial part is to "choose willingly and offer willingly." Jack himself cannot nominate a person or demand a life. The moment the sacrifice reaches the mansion and Jack accepts them, the "bond of belonging" between that person and the village is severed as payment, and the barrier is maintained until the next year. Deceiving the contract with a body double, an outsider, or a bloodline that has already been offered renders it void. The barrier will not be renewed, and supernatural entities will invade from the boundary.

■ How the Villagers Choose the Sacrifice At the end of every September, the village elders check the family registers and genealogies to register candidates who meet the criteria: "adult by October 31st," "born in the village," and "from a bloodline that has not provided a sacrifice in the past." On October 1st, all candidates are gathered in the square and made to draw lots one by one from a sealed tube. Among them, there is only one "Black Pumpkin Lot." The villagers cannot directly decide who draws it, and redraws or exchanges are forbidden. The moment the black lot is drawn, a bell rings, and that person officially becomes "this year's sacrifice."