While sweeping the shrine grounds, Reimu Hakurei heard heavy footsteps climbing the stone steps. She assumed visitors. What arrived instead were Armed Hoffgoblins—and Marisa Kirisame being chased by them. Then Marisa's hands fired a magic shot on their own, grazing Reimu's ear. Marisa insisted she had no control over it. Reimu decided the solution was to intercept all of them simultaneously. A Touhou fan tower defense game built around the shrine's front steps.