Shin Megami Tensei Online: Imagine

Shin Megami Tensei: Imagine, formerly known as Megami Tensei Online: Imagine, was a massively multiplayer online role-playing game (MMORPG) for Windows. It is part of the Megami Tensei series, and was developed by CAVE and later on GungHo Online Entertainment under license from the series creator Atlus. Originally released in Japan in 2007, it was later released in North America in 2008, then in Europe in 2009. Imagine is set between Shin Megami Tensei and its sequel, in the aftermath of a war which devastated humanity and prompted the arrival of hostile demons split into two opposing factions: Law and Chaos. The player character, a Demon Buster, is tasked with interacting with and fighting the demons that infest post-apocalyptic Tokyo. The gameplay uses real-time combat in open environments similar to other MMORPGs, while carrying over the Megami Tensei series' recurring demon recruitment and fusion mechanics.

Imagine originated as an attempt at developing an online version of Shin Megami Tensei: Nine for PC after Nine's online version was cancelled. The game's development lasted for over four years. For the first three and a half years, it was produced by Atlus as an online role-playing game. Development was then transferred to CAVE and continued for a further twenty months: during this period, it became and was marketed as an MMORPG. Upon release, it was critically acclaimed and attracted a large player following in Japan. The Western version was handled by multiple companies until its closure in January 2014. The Japanese version closed down in May 2016, nine years after beginning service.

The MMO was revived by fans again in November 2023 under a private server called Project New Moon.