In the secluded realm of Gensokyo, shrine maiden Reimu Hakurei works tirelessly to keep supernatural incidents involving youkai rare. Each year she hosts a summer banquet at her shrine, inviting a wide range of guests, from ordinary humans to powerful youkai. But on the morning of the event, the shrine’s donation box disappears without a trace, and no evidence of theft is found. Joined by her friend Marisa Kirisame and the news reporter Aya Shameimaru, Reimu investigates and discovers that others have also lost their possessions. As they follow the clues, the trio realizes that the theft is not ordinary, rather, it is a phenomenon on par with Remilia Scarlet’s mist or Yuyuko Saigyouji’s youkai cherry blossoms.