This is the story of a man lost in time, lost in his own memories and still regretting what could have happened if he acted differently at a specfific time in his life.
It's also the story of a 3 billion years old memory girl.
I enjoyed the art, right after finishing reading that in one sitting, it's like my brain was deep fried than put in the freezer. This manga is very complex and has a lot of layers in just 9 chapters but it's definitely worth trying. The way the story enrolls feels pretty natural, the narrator tells his life how it is, and he does it good.
I don't have anything else to say besides, it's hard to understand but it's still a good story.