Responses
Oneshots are often designed to pitch a series, like TV pilots. This one probably didn't get picked up.
After all of the one-shots I have read, I don't agree with the "often" part of your statement. I do agree that there are many promotion manga and webtoons, but there are just as many one chapter stories that actually have conclusions, even if they are subtle. But I do agree that this was probably made for a novel that didn't get enough interest for a proper manga series.
That didn't have any kind of conclusion or anything that a normal one-shot would have... This can't be it, right?