Why would anybody bother coming up with such a story if they don't want to give an end to it? Who's the editor fool enough to propose this for publication?
Two options:
1. The manga was cancelled and was mis-tagged as completed rather than cancelled.
2. The manga is ongoing, but the status was mis-tagged as completed.
pretty good, but for being only 4 chapters long, youd think it would be a bit tighter of a story. that ending is only called that cause theres no more chapters.