To all those who come to the comments section wondering about if this manga is really over or not: it says it's "completed" with 6 volumes, but...
https://www.amazon.co.jp/gp/product/4592161777/ref=crt_ewc_title_huc_1?ie=UTF8&psc=1&smid=AN1VRQENFRJN5
There's the official Amazon JP page for...