This is a collection of 50 very short stories. Many of them are Sci-Fi. Most of them are humorous with a handful that are just creepy. The stories are short and usually have a punch line, so it is kind of like reading jokes. Some are satire, cautionary tales, or something like fables.
Also, the humor doesn’t depend much on the details of Japanese language and culture. Some of the jokes may be a bit simple or crude, but you don’t have to worry that they will be lost on you if you don’t share the same lifetime of experiences as a typical person living in Japan.