Some time ago, Shunsaku Ban witnessed his friend’s murder during a random robbery attempt, and decided to become a guardian for the man’s infant son, Yuno. The child instantly bonded with a mysterious green cat that was carried by the gang, but Shunsaku was convinced that there’s something nefarious about the feline. Now, in the present, his long lost child surfaces in the news as a rich and powerful man who’s having the best luck at the casinos - and somehow, the green cat is still alive and at his side. Determined to save Yuno from the clutches of this evil creature, Shunsaku begins to investigate the truth of what’s really going on...

얼마 전, 슌사쿠 반이 무작위 강도 미수 사건 중 친구의 살인을 목격하고, 그 남자의 갓난 아들 유노의 후견인이 되기로 결심했다. 아이는 곧바로 패거리에게 끌려온 신비한 녹색 고양이와 유대감을 맺었지만, 슌사쿠는 고양이에게 뭔가 사악한 것이 있다고 확신했다.