2 Years of Service
that and sometimes they dont even have the begining made, just the world and the idea, for example, Naruto, if one starts looking at the start you will find many plotholes and plot forced situation that makes no sense and are just there to force drama, many characters with a huge lack of common sense too. In general they would benefit for making the start and the end before starting the story.as far as "lack of proper endings" go, I think one issue that a lot of manga authors have is that they don't have the whole story planned out from the start and as a result the beginning of teh story is good but falls off in the end