Japanese-American Kevin Yamagata now authors the renowned detective comic book "Billy Bat" after serving in the Allied Forces in World War II. But as his series becomes a massive hit, Kevin discovers that his famed character, Billy Bat, already existed before within a Japanese comic. Worried that he may have unconsciously copied something he saw during his time there, Kevin returns to Japan to find Billy Bat's original creator and seek permission for him to use their character. However, as he traces back Billy Bat's roots, he finds himself unraveling a dark and twisted history of murders that somehow involve the character he thought he created.