Useless Ponko is one of my favorite manga and despite its length, it's criminally underrated. Basically, a man's late wife sends a robot maid to take care of him. Unfortunately, she's pretty clumsy and he doesn't like her at all at first, but their relationship grows at a nice pace. Overall, the story is about their numerous days and adventures together, as well as their time in the town they live in.
The comedy is pretty good, the characters are all likable (I didn't like the granddaughter at first, but I quickly warmed up to her in the next 2 chapters she was in), and when it wants to be, the story is relatively heartwarming. I'm not the type to read this kind of manga, but it's already got me hooked.
It deals with loss, change, acceptance, and other things, and does a good job instilling lessons concerning these topics. The art is cute, especially how Ponko and the granddaughter are drawn. And thank god the children aren't sexualized like so many other manga with cute child characters do. Overall, a good manga to read in your spare time, especially if you're looking for an innocent slice of life!