Catman is still as unlucky as ever, to the point where even falling from a building leads to him to become an enemy of the cheese-bearing mafia! Though his life is anything but dull due to encounters with flirtatious booze hounds and street gamblers, Catman is content to live the way he wants: moving from one drink-fueled brawl to the next.
Every town needs a hero. Unfortunately for the human residents of Dark City, theirs is a stray cat. Swooping from roof to roof, its first thought is always of food or being able to catch an elusive mouse – saving the day is just a fortunate side effect. From rescuing lost children to putting a stop to careless littering, Dark Cat finds himself caught up in numerous problems – though caring about none of them. As his name spreads, he finds himself the center of attention as reporters desperately try to snap the unlikely hero. Cheeky and mischievous, this feline favorite wants to protect his kind; but can this renegade kitty stay out of the clutches of a mayor determined to rid the city of strays?
Both series take a look at cats in the human world that cause interesting situations. Dark Cat actually has humans in the show where Catman turn cats into human like beings living out their daily lives. Both have a interesting soundtrack that helps the viewer feel more about the show, especially in Catman. Both are abstracty in their style and have short episode lengths, if you liked one I'm sure you'd enjoy the other.
If you enjoyed watching Catman get caught up in various situations and generally causing mayhem, then it's really worth checking out Ankoku Cat who is also entirely mischievous, but with good intentions at heart.
Both these titles feature a cat as the main character, who both fall short of being a hero, no matter how much they'd like to be one. Although in Catman III, the animation style has changed quite a bit compared to it's prequels, I'd still recommend watching Dark Side Cat as well.