It's part of a bigger licensing deal between Comicsmart and Mangamo. The English version has already started to be released, but it's only available in the Mangamo app. First three chapters are available for free, 25 have been released so far.
This is just an exception, later chapters do have...
The three "volumes" were doujin booklet releases of the already existing chapters.
The title is now going to be serialized, though, and those already existing materials along with some new stuff will form the official volume 1 book that is coming out in November in Japan. So new chapters will...