Since many people are disapointed (and they are right) with the end.
We can try to convince the author (and an editor) to do a sequel or ad missing part (partialy redcon the end so he can continue the story)
but for that we need two thing, one really easy, the other one "harder"
first= talk to the mangaka on how much you like it but you would like more (is twitter @irumo)
secondly (the hard one)= buy the manga on bookwalker (i understand if you can't, but i think that the most important part unfortunately).
If they are enought people i am sure some people (the author and editor) would give it another chance. (even one year later)