Kyuu is your average boy with a knack for logic and reasoning. Desiring to become a detective, he finds out about the existence of the Dan Detective School (DDS); a famed school where students are allowed to bear arms. Together with Megu, a girl with photographic memory, the martial arts master Kinta, the genius programmer Kazuma and the mysterious Ryuu, Kyuu tackles many well planned out crimes, always seeking the truth.

Kyuu is your average boy with a knack for logic and reasoning. Desiring to become a detective, he finds out about the existence of the Dan Detective School (DDS); a famed school where students are allowed to bear arms. Together with Megu, a girl with photographic memory, the martial arts master Kinta, the genius programmer Kazuma and the mysterious Ryuu, Kyuu tackles many well planned out crimes, always seeking the truth.