Planetarian: The Reverie of a Little Planet is an anime-style first-person visual novel adventure. The game takes place in a post-apocalyptic world. Due to dwindling natural resources, overpopulation, and the failure of the space exploration project, humanity is said to have virtually eradicated itself through biological and nuclear warfare, reducing a once thriving civilization to complete destruction. One military invasion in the past was on Mara Nectaris. The bloodshed continues 30 years after the war in a dystopian world, through automated fighting machines that kill anyone who trespasses on their territory. Of the remaining people, there are those known as junkers, who are looking for something to survive; the main character of the story is one of them.