As summer break commences, Watanuki finds himself working for Yuuko's unique shop while his peers enjoy their seasonal freedom. Despite the spirits and other supernatural occurrences decreasing in frequency, Watanuki remains indebted to the seemingly lazy Yuuko by completing tasks such as cleaning and cooking. A new dilemma arises when Yuuko receives an enigmatic invitation to a mansion, whose owner wants to exploit her ability to grant wishes. As Watanuki, Yuuko, and Shizuka Doumeki embark on the curious journey to the estate, they encounter other invitees who share a passion for collecting rare and peculiar items. However, the excitement turns to concern as guests begin to vanish one by one, forcing the trio to solve the mystery before they too become victims of danger.