This is it, no longer would any other mangas ever attempt to be called masterpieces, they're all shallow puddles compared to the ocean full of depth that this intricately written and beautiful drawn manga achieves. The author must have bleed his hands meticulously trying to put each and every intricate details into this masterpiece of a manga. If anyone asks you about best manga ever written and you fail to mention this particular manga, you've failed as a fellow manga reader my learned friend.
Shinseki no Onee-chan