His name is Kuro and he's a cat. His owners are an old couple who live a simple, easygoing life. But because they have money, thieves often try to raid their home. Each time, however, Kuro manages to fight them off. Kuro is a great watch cat.

One day, however, Kuro is shot through with an arrow and whisked away by Doctor Go, an evil scientist. Doctor Go turns Kuro into a cyborg to assist him on his mission to conquer the world.

Doctor Go tries to control Kuro, but Kuro manages to escape. This infuriates the doctor. He feels that Kuro is ungrateful to him. With the help of Mi, another cyborg cat, he thinks of all sorts of ways to capture and kill Kuro.

Kuro has a new, invincible cyborg body, complete with the latest hi-tech weapons. But he also has a warm heart, which is partly what makes this story so loveable.