Planetarian: Chiisana Hoshi No Yume

Planetarian: Chiisana Hoshi no Yume (planetarian ～ちいさなほしのゆめ～?, lit. Planetarian ~The Dream of a Little Planet~) is a Japanese post-apocalyptic visual novel developed by Key, a brand of Visual Art's whose previous works include Kanon and Air. It was released over the Internet on November 29, 2004 playable on Windows PCs and is rated for all ages. The game was later ported to the PlayStation 2 (PS2) and PlayStation Portable, as well as mobile devices. the story centers around a middle-aged 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.

Key defines Planetarian as a "kinetic novel", since its gameplay offers no choices or alternate endings. Instead, the player proceeds through the story solely by reading. The story is written by Yūichi Suzumoto and Planetarian is one of two Key games not to have Itaru Hinoue as an artist, using Eeji Komatsu instead. The game's soundtrack was composed and arranged by Key's signature composers Magome Togoshi and Shinji Orito. A light novel of short stories set in the world of Planetarian was released in April 2006, and three audio dramas have also been produced. In the February 2007 issue of SoftBank Creative's Gemaga magazine, the PS2 version ranked first for console games in terms of satisfaction; the game had ranked fourth in the previous issue.