The focal point of the tale is Testa, a youthful linguistics prodigy and university professor. Sergeant Rossa, his elder, introduces him to the Allied Cryptanalysis Department where he is assigned the duty of decoding the enemy werewolves' communications, which are encrypted using a wolf's howl. Despite his extensive research, Testa struggles to decipher the code and decides to capture a live werewolf to improve his cryptanalysis. After exhausting all options, he ultimately discovers Yonaga, a female werewolf.