Since the birth of humanity on Earth, various civilizations have emerged in countless places, repeatedly experiencing cycles of prosperity and collapse. People, who have become rich both materially and spiritually, were eventually on the verge of undergoing a great social transformation. The story is set in a small country located in a certain northern region. It has a cool climate throughout the year, a high rate of clear skies, and is known as the "Star Castle" because one can see a sky full of stars at night.

In "Star Castle," a religion called the "Aster Faith" had taken root. The doctrine of the Aster Faith is "reincarnation," and it is believed that people still bear the sins of having defied God long ago, which causes them to repeat the same mistakes.

"Sumire" and "Shion" were children who had escaped from kidnappers and were living on the streets. The boy named "Subaru," who happened to meet them by chance, was the current leader of the Aster Faith and was revered by his followers as a "God." Subaru extends his hand to the two of them.

"This meeting must be fate. Will you come with me?"

[Translated from the official website.]