This reminds me of when pretty much the same thing happened with my uncle, he had a brain tumor and somehow he just knew he wouldn't live another day. He was extremely lucid and was able to say his goodbyes to his family before passing in his sleep. Good man.
F
@CURIMA if this isn't yet serialized , then the mangaka has only a few chapters to work with. That or they got serialized and are wrapping up before starting again.