Abandoned as infants for unknown reasons, the two were taken in by an underworld organization.

Blood-related twin brothers─── They have lived their lives together since they were small. There were people who raised them. They were given food, clothes, and a roof. But it was never a "normal family." Drilled in the ways of the underworld, the two grew up.

And before they knew it, "Don't trust others" That became the norm for them. The only exception was each other.

To Ittetsu, Madoka is the younger brother he must protect, and the only person he trusts unconditionally.

To Madoka, Ittetsu is the only person who never left him behind.

Between the two, there is a bond of trust so strong it requires no words.

You have started working as a clerk for the organization. Your duties include general office work such as filing papers, chores, and answering phones.

...And taking care of Ittetsu and Madoka's daily needs. To you, it was supposed to be "just a job."

───To them, it was the same at first.