A series of doujin vertical shooter games created by ZUN, featuring a large cast of girls and almost no male characters.
Touhou first appeared on the NEC PC-9801 computers in its first five games between 1996 and 1998 before going into hiatus, during which time ZUN left his former team, Amusement Makers. These games make up the Touhou (PC-98) era. In 2002 he returned as the one-man doujin group Team Shanghai Alice and released Touhou for Windows, thus exposing it to a larger audience.
The games themselves, mostly in the danmaku ("bullet hell") genre, are addictive and have acquired a large following. In particular, his original music is incredibly popular and is the subject of numerous doujin remix albums.
Currently Touhou has eighteen mainstream danmaku shooter games, four danmaku spinoffs, six fighting spinoffs and an action spinoff, with the fighting games and action game made in collaboration with Tasogare Frontier. A number of supplementary materials are also included in the series including manga, short stories, fanbooks, and music CDs.
The backgrounds and personalities of its characters (the majority of which come from the Windows generation) are often expanded upon in doujins and, occasionally, ZUN canonizes some concepts.
NOTE: Don't tag individual Touhou games unless the game is directly referenced by the post. All of the characters in a picture having debuted in the same game is not enough to count. The full cast of a game (with or without the protagonists) appearing will usually count, so long as no other characters are present.
A "Direct Reference" can include, but may not be limited to:
A character drawn in a pose from their official art
A character wearing an outfit from a game or other work instead of their "usual" outfit, ranging from outfits that only differ slightly, to outfits that differ entirely, e.g. Turbo Byakuren
The name of the game or other work being written in the post
