Showa 73 — Imperial Capital.

The protagonist was living a blessed, uneventful life.
Loved by her father and treated kindly by those around her, she was simply enjoying peaceful times in a wealthy home within a vast estate.
She thought that was just fine.

One day, a notice arrived from the Phantom Thief Thirty-Two Faces, whose name was well-known by many.

"I shall come to take the most precious thing from this house."

The world around suddenly became tumultuous.

Around that time, besides the incidents involving the Phantom Thief Thirty-Two Faces, a series of cat and dog killings were also making the rounds in the news.
Small but horrifying incidents where stray animals were found with their abdomens ruptured.
There was growing concern that this soon might extend to humans.
In the midst of this chaotic situation, the father, as if imposing 'normalcy,' hires a new tutor for the protagonist.
And as if to further strip away the 'normalcy,' the protagonist's life starts to be targeted.
The attack of the Phantom Thief Thirty-Two Faces — the series of cat and dog killings — the dangers that keep coming one after another.
Betrayals and schemes, doubts and truths.
'Reality' is beginning to show its face.
Will the protagonist be able to reach the true conclusion?

[Translated from the official website]