Touhou Koumakyou ~ The Embodiment of Scarlet Devil is a 2002 bullet hell scrolling shoot 'em up video game developed by Team Shanghai Alice. It is the sixth game in the Touhou Project series, and the first Touhou game to be released for Microsoft Windows. The story follows either the miko Reimu Hakurei or the magician Marisa Kirisame, as they fight through the world of Gensokyo to find the cause of a vampiric mist, covering the sky scarlet red in the middle of summer.

Touhou Project , also known simply as Touhou , is a bullet hell shoot 'em up video game series created by one-man independent Japanese doujin soft developer Team Shanghai Alice. Since 1995, the team's member, Jun'ya "ZUN" Ōta, has independently developed programming, graphics, writing, and music for the series, self-publishing 19 mainline games and 13 spin-offs as of October 2023. ZUN has also produced related print works and music albums, and collaborated with developer Twilight Frontier on seven additional official Touhou spin-offs, most being fighting games.