Summer break has arrived, but while his other classmates are out having fun, Kimihiro Watanuki continues to work as compensation for the eccentric Yuuko in her shop. With the spirits and supernatural phenomena that bother him lessening, he pays his dues by cleaning, cooking, and doing whatever else the apparently lazy Yuuko needs. Watanuki, however, gets involved in a new predicament when Yuuko receives a mysterious invitation to a mansion whose owner seeks Yuuko's wish-granting ability. When he, Yuuko, and his classmate Shizuka Doumeki make their way to the peculiar residence, they meet others who were summoned by the same strange invitation. All of them are collectors of various unique items, drawn there by the chance to expand their collections. But as the collectors begin to disappear one by one, Watanuki and his companions must solve the mystery and put the case to rest, or find themselves in risk of danger.

The fifth film in Shin-Ei's series of annual WWII themed anime television movies for children Sensou Douwa (war story). (Source: AniDB)

Ten years after the events of xxxHOLiC Shunmuki, a melancholic Kimihiro Watanuki has taken over the shop formerly run by the mysterious Yuuko due to a promise he made to her. His companions Maru, Moro, and Mokona live together with him in relative contentment, and some familiar faces arrive every now and then: former rival turned-steadfast friend Shizuka Doumeki, and the former psychic prodigy Kohane Tsuyuri. While Kohane studies folklore under Doumeki at university, they encounter a case that is perfect for the master of the shop. Eventually, Watanuki receives a visit from Doumeki's grandfather, Haruka. He requests that Watanuki investigates his grandson's dreams. While inside the dream world, he discovers how their past adventures played out from Doumeki's perspective of view, leading Watanuki to discover truths from 10 years ago and secrets about the ties that bind their friendship.