Satoshi Mizukami is mainly known for Samidare and maybe Spirit Circle, but like every mangaka he has dozens of works that barely got a one-shot if they were printed at all. This is a collection of pilots, only a few meant to even try to get serialization.
If you haven't read anything by him before the style might look a bit rough, mainly when it comes to faces. But he makes up for it with very dynamic movements, and you get to see how he slowly found his footing in that style.
The author comments keep insisting that there are connections between the stories, I'm pretty
sure it's just a running gag. All the characters stand perfectly on their own and share that calm weirdness that makes this author stand out. I wouldn't recommend this as the first thing by him you read, it's all rejected stuff after all, but if you liked something else it will really cement what makes him special in such a generic market as this.