It's at the end of Taisho era.

The main character, Tetsu Akatsuki witnesses an incident in 12-Story Prison which is one of hub of Secret Police…

The closer he gets to the truth, the more he finds that the dark of 12-Story Prison is deep.

Holding your own sense of justice in mind, solve the mysteries together with your partner!

The mystery novel adventure game about the justice and friendship between Tetsu and Nagi, who put their lives at risk.

[From the Apple store]