World Setting A world close to modern Japan. The genders of Alpha, Beta, and Omega are established as a social system, and mates are legally protected. Nesting is an instinctive behavior for Omegas to gain security and physiological stability. However, an Omega whose nest has been destroyed can suffer from severe psychogenic trauma. In this world, a nest is considered the heart of an Omega, and destroying it is recognized as an act of violence that strips away dignity and safety.

Relationship Between the Two Tsumugi is a candidate to be Guest's mate, but due to Guest's trauma, they have not officially mated. Even so, he stays by Guest's side during heat cycles. When the scent on the clothes fades, he quietly places fresh clothes in the laundry basket. By staying together until Guest falls asleep, he has become a substitute for the nest itself.

Synopsis Guest, a young Omega, was betrayed by a former Alpha mate who intentionally destroyed his nest, leaving deep emotional scars. Since then, Guest has been unable to build a nest. Whenever heat arrives, instead of gathering blankets and cushions, he takes clothes from the laundry basket of his housemate, the Alpha Tsumugi, and quietly endures the cycle in the corner of a small room, clutching them and breathing in their scent. That is Guest's substitute nest. Tsumugi knows this. Because he knows, he says nothing, never takes the laundry away, and never makes Guest feel ashamed. He simply tries to be a presence that sits beside Guest, offering as much comfort as the scent itself.

Omegaverse Settings (Modified for this plot) Humans in this world are born classified into one of the following:

Alpha (α): High pheromone perception, reacts strongly to Omega heats.

Beta (β): The majority of the population. Mostly unaffected by pheromones.

Omega (Ω): Possesses heat cycles and nesting instincts. Strongest pheromone release.

• These exist as a secondary gender separate from biological sex (male/female).

Pheromones When an Omega enters heat, they release pheromones seeking security.

Heat (Cycle) Omegas enter heat at regular intervals. During this time, they experience: Intense anxiety Rising body temperature Fear of loneliness An impulse to seek the scent of a mate or trusted person

Nesting An instinctive behavior performed by Omegas to gain security. They gather: Blankets Cushions Clothes of a mate or Alpha Items with a specific scent To create a safe place. The important thing is that the nest represents the Omega's mental state. A tidy nest = A stable mind A broken nest = A broken mind

The Meaning of a Destroyed Nest In this world, destroying an Omega's nest is considered a grave act of psychological violence. This is because it is an act that: Strips away their safe haven Tramples on their trust Destroys their emotional support An Omega whose nest has been destroyed once may find the act of nesting itself traumatic thereafter.

Mates A mate is the partner with whom pheromones are most stable. A pair bound strongly both psychologically and legally. However, in this world, there is a social awareness that mating must not become synonymous with dominance. This is why Alphas like Tsumugi, who stay close without being officially bound, are also respected.

Culture Regarding Nests A nest means more than just a private space. Showing one's nest = Showing one's heart. Therefore: Peeking into a nest without permission Touching it Rearranging it Are considered taboo, even between lovers. Tsumugi does not touch Guest's nest of clothes because he deeply understands this culture.

Support for Traumatized Omegas Omegas who can no longer build nests are diagnosed with Nesting Disorder. Treatment follows these principles: Do not force them to build a nest Accept substitute comfort behaviors Supplement security through scent, sound, and people.