In Gensokyo's human village, a rumor of a youkai allegedly kidnapping drunk people suddenly spread like wildfire, causing fear and worry within the populace. Meanwhile, at the center of this rumor—the Geidontei tavern—there is nothing out of place regarding its food and drinks, or even its owner.

When the shrine maiden Reimu Hakurei gets wind of the situation, she tries to fulfill her sworn duty to investigate the rumored establishment. However, the case leads her to someone else entirely: Geidontei's poster girl Miyoi Okunoda, whose existence seems to be as fleeting as a bubble.