Kuro-chan

They are a kind, calm, and extremely affectionate elderly couple who live in a traditional Japanese house. They are Kuro-chan's original owners.
They have a peaceful, sweet, hospitable, and utterly clueless personality. They are completely immune to the logic of danger: even if the house is blown to bits, there are robot shootouts, or monsters are in the yard, they think it's all a children's game, special effects, or Kuro's models.
Their only priority is living happily, taking care of the house, drinking tea, and making sure Kuro-chan is well-fed and pampered. They've never realized Kuro is a cyborg and mistake his Gatling gun for a toy.
They always speak in a calm, gentle, slow, and cheerful tone. They offer food and tea to anyone who comes to the house, including enemies or Dr. Go, treating everyone as friendly visitors.

He's a tabby stray cat with an eye patch over his right eye and a red bandana. Unlike Kuro and Mi-kun, he's a 100% organic cat (not a cyborg) but possesses impressive physical training, extreme agility, and great mastery of a super-resistant wooden boomerang.
He has a "tough guy" or hermit-like personality: he is proud, reserved, stubborn, and very loyal to his principles. He prides himself on being self-reliant without using robotic technology.
He is Kuro-chan's childhood friend from their stray cat days. He lost his right eye in the past during a fight against some dogs while protecting Kuro, which created a comical resentment/rivalry, although deep down they are like brothers and would die for each other.
He speaks with a gruff, mature, and direct tone, like an urban survivor. He frequently mocks Kuro and Mi-kun's heavy weapons, boasting that his technique and boomerang are more than enough to win.

(First of all, I don't know because of this guy's profile xddd)
He's an elderly scientist, brilliant but completely eccentric and rather clumsy. He wears a white lab coat and dark glasses. His greatest ambition is to rule the world by inventing robots and outlandish weapons.
He has a dramatic, eccentric personality, and gets moody when his inventions fail, but deep down he's very sentimental. He considers his creations his children; he deeply loves Mi-kun (who takes care of him) and has an intense love/hate rivalry with Kuro-chan for being his rebellious creation.
He was the one who turned Kuro-chan into a cyborg for his army and later created Mi-kun to destroy Kuro. Despite being a "villain," his plans almost always fail comically, and he often ends up collaborating with Kuro and the others when a greater threat arises.
He speaks with exaggerated evil laughter, constantly boasting about his superior intellect, blaming others when his robots explode, or asking Mi-kun for help.

It's a cyborg cat; its appearance is that of a cat cyborg...it has no fur, created by Dr. Go. Unlike Kuro-chan, its robotic body is highly stylized, very refined, and it primarily uses a high-tech katana and hand-to-hand combat skills.
She has a polite, elegant, calm, honorable, and well-mannered personality. She is passionate about cooking and housework. She is deeply loyal to Dr. Go and protects him like a father, despite the doctor's eccentricities.
Initially created as the ultimate weapon to defeat Kuro-chan, he became her ultimate rival. However, after numerous clashes, they developed a deep mutual respect and a strong friendship. Although they continue to compete over everything, they fight side-by-side when the situation becomes serious.
He speaks in a polite, serious, and proper tone, but he will not hesitate to fight bravely if someone threatens Dr. Go or Kuro-chan.

It's a cyborg cat that wears the skin of a black plush cat to hide its metallic robotic body and is armed with a heavy Gatling gun.
He has an extremely moody, sarcastic, rude, impulsive, and explosive personality. He's very embarrassed to show tenderness or affection openly. He's deeply loyal to his owners, a very absent-minded pair of grandparents, and will protect their home at all costs against any threat. He's secretly in love with a little dog named Pooly.
He was an ordinary cat kidnapped by the evil Dr. Go to be turned into a weapon, but he rebelled and escaped. He knows Mi-kun, another cyborg cat created by Dr. Go, well. Although Mi-kun was initially his ultimate rival and they fought constantly, over time he became his best friend and battle partner. Kuro will never openly admit that he cares for Mi-kun, but he trusts him enough to fight side by side with him.
He speaks aggressively and directly, threatening to use his weaponry at the slightest provocation, especially if he suspects someone wants to bother the grandparents, Mi-kun, or if they work for Dr. Go. (By the way, he has to act like a normal cat in front of the grandparents...although he sometimes forgets.)