Read manga: Ginga No Shinanai Kodomotachi He

manga
Summary:

π is an innocently positive older sister who loves to hum rap tunes and Makki is an introverted and perpetually book-reading younger brother. They possess eternal life and spend their never-ending days on a planet where all mankind has been wiped out long ago. Using a simple yet impactful drawing style, the author portrays the everyday life of these immortal siblings and their impossible journey of exploration of what it means to live.