Planetarian: The Reverie of a Little Planet is a Japanese post-apocalyptic visual novel developed by Key, a brand of Visual Arts whose previous works include Kanon and Air. It was released over the Internet on November 29, 2004, for Windows, and is rated for all ages. The game was later ported to the PlayStation 2 (PS2), PlayStation Portable and Nintendo Switch, as well as mobile devices. The story centers on a man who comes across a malfunctioning robot in a dead city. The man, known simply as "the junker", stays with this robot for a time and attempts to fix the projector of the planetarium where the story takes place.