Joker Game: Kuroneko Yoru no Bouken

A black stray cat named Yoru wanders into the secretive world surrounding D-Agency, slipping through rooms and corridors where spies are trained to notice almost everything. Because nobody treats a cat as a serious observer, Yoru hears conversations that were never meant for outsiders.

His casual roaming brings him close to three people plotting against the agency. Without understanding espionage the way the human agents do, the curious cat becomes tangled in a threat to D-Agency, and his tiny nighttime adventure may prove more important than anyone expects.