Kagerota, a young ninja of the Kiryu family, has lived without feeling affection. His father Kenzan is a legendary red-nosed ninja. Kagerota parted from Kenzan at the age of 10 and loses all contact with his father.

One day, Kagerota goes to the city of Edo with his fellow ninja for a mission. It is an easy task of stealing a special golden fish from a Daimyo Yashiki house. Kagerota sneaks into the house successfully. Just when he leaves with the fish, Kagerota feels a creature’s presence close by him. It is a red-nosed fat cat. The cat makes him nostalgic as it looks somewhat alike his father.

　　《猫忍》由《猫侍》原班人马打造，是世界首部“猫类忍者”动作片。 阳炎太是一个游手好闲的年轻忍者，他的族人认定他知道传说中的卷宗的下落。相传，那上面记载着能够帮助战士赢得胜利的易容术技巧。他随身带着自己的“父亲”，一只有着金毛红鼻的肥猫。阳炎太相信，这只肥猫是自己离世的父亲，传说中的忍者剑山，因为肥猫有着和父亲一模一样的红鼻子。与此同时，宗族长老为了能尽快得到卷宗，派出了两名女忍者红叶与燕，去抓捕阳炎太。而阳炎太为了使自己的父亲能够显出人形，开始避人耳目地养猫……

젊은 엘리트급의 닌자가 아버지의 얼굴과 어쩐지 분위기가 닮은 고양이와 만나게 되고, 닌자의 법도를 깨고 고양이를 사람들의 눈을 피해 기르기 시작하면서 벌어지는 이야기를 그린 드라마