At the core of the tale lies Testa, a brilliant linguist and university teacher. Sergeant Rossa, his senior, introduces him to the Allied Cryptanalysis Department, where he receives an assignment to decode the werewolves' encrypted radio transmissions. Testa is baffled by the fact that the code produces only the sound of a wolf's howl. Despite conducting extensive research, he is unable to break the code and decides to apprehend a living werewolf for more effective cryptanalysis. Despite his tireless efforts, he eventually comes across a female werewolf named Yonaga.
