Touhou Spell Carnival is an officially recognized derivative work based on Touhou Project. Gensokyo — A remote land isolated from the Outside World, where humans and youkai live side-by-side. One day, the shrine maiden of Hakurei Shrine, Reimu Hakurei, spots mysterious pillars towering over various locations throughout Gensokyo. These pillars signaled the start of the Spell Carnival, a festival hosted by Yukari Yakumo where one must put their Spell Cards on the line in battle. In order to investigate the true intentions of Yukari Yakumo, who initiated the Spell Carnival so suddenly, Reimu Hakurei joins the fight for Spell Cards.