Well... everybody dies. And I think that it doesn't actually make the difference if somebody visit your tombstone or not, neither did you leave something under your name or not.
It's all the same for dead people. ¯\_(ツ)_/¯
This series is actually like a practice sketchbook whereby I force myself to draw as nicely as possible (with storyline) as i try not to edit it in anyway other than darkening/adding text for easier reading purpose.
Story wise, they're inspired by the picture books in Naoki Urasawa's Monster. I would say this is a picture book about life and values.