Summer, 2000.

In Kusaka Village, a secluded settlement deep in the mountains of Shinshu, preparations for a festival were quietly underway.
It was a secret rite, held only once every nineteen years, called The Moon-Waiting Ceremony.

The ceremony was presided over by the Kuraki family, who have dominated this land since ancient times. They lived in a magnificent Western-style mansion overgrown with blooming flowers, known as the Camellia Mansion, a mysterious clan that adhered to its own unique customs.

The protagonist, Hayama Kouichi, is summoned by the head family, the Kuraki clan, and sets out for the Camellia Mansion. He suffers from a strange illness that prevents him from recognizing women's faces, is tormented by daily nightmares, and on that day, he arrived as if he had been carried in, having been seized by hallucinations.

However, when he wakes up from his nightmare at the Kuraki residence, he suddenly becomes able to see women's faces clearly. The person he sees is Kuraki Suzuna. This house's only daughter and the Moon-Waiting Priestess.

Kouichi is eventually told that he will become the head of the Kuraki family and is ordered to stay in the mansion until The Moon-Waiting Ceremony one month later—

[b]What will blossom at the end of the secret rite held in this mysterious village—