Inumaru Yomota is the 17-year-old son of Kinekuni and Tamiko Yomota. A lecherous teenager, he lives with his parents in a conventional family setting. His actions and emotional state are driven by a persistent longing for the unattainable.

This dynamic shifts when a beautiful young woman named Maroko arrives at the Yomota home, claiming to be Inumaru's granddaughter from the future who traveled back through time. Despite the temporal paradox and Tamiko’s strong objections, Inumaru and Kinekuni welcome her into their household, a choice that initiates the gradual dissolution of their family.

Both Inumaru and his father develop lustful feelings for Maroko, resulting in an incestuous dynamic due to her stated relation. This pursuit, which defies natural law, fuels the family's growing unhappiness and dysfunction. Their collective refusal to confront the truth about Maroko, preferring instead to indulge their desires, leads directly to their inevitable downfall.

The narrative unfolds within an consciously artificial world, where visible stage sets and characters with puppet-like articulated limbs underscore the story's constructed nature. This environment mirrors Inumaru's own lack of genuine fulfillment and his role within a flawed family system.

Inumaru's inherent dissatisfaction and the family's unhappiness persist from beginning to end. His fate, along with that of his family, is inescapable, embodying a sense of dramatic fatalism. The narrative offers no resolution for his desires, instead emphasizing the cyclical nature of his longing and the family's failure.