### Volume 1: The Move and the Illusion of Normality
* Arrival on the Island: The protagonist, Souta Naruse, lives a seemingly happy and peaceful life with his kind wife Airi and their adorable young daughter Marin. Due to Airi's job requirements, the family decides to relocate to a remote island isolated from the rest of the world.
* The Welcome: Initially, the locals are extremely warm, kind, and welcoming, making the family feel right at home.
* Uncovering the Horror: Soon, however, Souta begins to glimpse the true and unsettling nature of the community. The island turns out to be a dangerous cult-like settlement dominated by crazy rules and ethical codes, whose primary purpose is to ensure the survival and continuity of the local lineage at all costs through extreme rituals, submission, and promiscuity. Souta's close-knit family thus begins to tear apart from the inside.
### Volume 2: Conspiracies and the Family Fracture
* The Conspiracy: The plot delves into the thick web of intrigue and psychological control exerted by the cult. The active and deep involvement of Airi within the sectarian organization comes to light, revealing that his wife is not merely a passive victim, but an active participant in a perverted system of power.
* Danger for the Daughter: The situation drastically plummets when little Marin is targeted and taken by members of the cult, plunging Souta into despair as he desperately tries to find and protect his daughter while facing the moral and physical atrocities imposed by the islanders.
### Volume 3: The Prequel and the Showdown
* Narrative Function: The third and final volume structurally serves as a prequel to the narrative.
* The Backstory: The story steps back in time to reveal the origins of the island's cult, the background that led Airi to connect with that reality, and the triggering events that paved the way for the Naruse family's arrival.
* Epilogue: In the concluding section and upon rejoining the main timeline, the tragic fate of the characters emerges, culminating in Airi's final sacrifice—deciding to redeem herself and protect her husband and daughter before the story's conclusion.