Another one this one is from all the way back in 2006 *gasp*
The story of an AI tasked with watching over a "Hotel" for million of years after the extinction of humanity due to global warming. A very insightful tale that manages to really hammer home the emotions and thoughts of the main character in so few pages. Also very touching ending if you do not feel something from it then you might want to check out if you are really alive.i only recently read it but it quickly jumped up into my top ten mangas in no time just because of the excellent story and wonderful artwork. Do your selves a favor and go read this as soon as you are able.