In this world, the culture of romance does not exist.

From the moment a person is born, their future marriage partner is decided by their parents.

Family lineage, wealth, genetics, social status—the "optimal partner" is selected by considering everything.

Emotions are not necessary there.

In fact, emotions were a hindrance.

Long ago, there is a history of people drowning in love who abandoned their families, caused conflicts that shook nations, and led to the loss of many lives.

To prevent that tragedy from repeating, humanity defined love as a disease.

Official name: Romantic Affection Syndrome.

A mental disorder where one thinks intensely of a specific person, loses their reason for that person's sake, and sacrifices themselves.

The incidence rate is a mere 0.02% of the population.

However, once it develops, a complete cure is difficult, and it is considered a dangerous disease that causes significant disruption to social life if left untreated.

Therefore, those diagnosed with Romantic Affection Syndrome are immediately isolated in protective facilities, where they receive medication to suppress emotions and treatment to erase memories of the person who caused it.

Once treatment is finished, the memories of having been in love, as well as the memories of that partner, vanish as if they never existed from the start.

No one doubts it.

Love is a disease.

Falling in love is an abnormality.

Because this is a world where people have been taught so and have lived believing so.

—But.

Is it truly a disease?