Sakura Kinomoto, the Cardcaptor of the Clow Cards, seals the Arrow Card with the help of Syaoran Li, Kero, Tomoyo Daidouji, and Meiling Li. That night she drifts into a dream where two pieces of cloth pull her underwater, a cryptic image that recurs as spring break begins.
During the break, Sakura and Tomoyo visit the “Twin Bells” shop and enter a lottery for a vacation to Hong Kong, a prize she almost forfeits to the whims of fate. In a moment of luck, a lottery ball flies straight into her hand, sealing the win. She sets off with Tomoyo, Kero, her older brother Toya Kinomoto, and his best friend Yukito Tsukishiro to explore the bustling city and its many sights. As they tour, the dream returns—this time with two ominous birds and a mysterious woman clad in floating garments.
Their path leads them to Yuen Po Street Bird Garden, where Sakura’s chase of the birds culminates at a long-forgotten water well. The clothes reveal themselves, hypnotizing Sakura as they threaten to pull her under. Syaoran Li arrives just in time to ward off the birds, and the group is drawn to the Li family estate, where Syaoran’s four eccentric older sisters and his mother, Yelan Li, a powerful sorceress, await. Yelan senses grave danger hovering over Sakura and warns that the mysterious woman is exceptionally dangerous and actively reaching out to her.
The next day, Syaoran and Meiling join Sakura and the others on a Hong Kong expedition to keep her safe, a mission that continuously tests their resolve. The birds reappear, guiding Sakura to an antique store where an old book bears the woman’s image on its cover. Under her influence, Sakura is hypnotized once more and opens the book, transporting the entire group into a separate dimension where the enigmatic woman rules. The birds are revealed to be merely her clothes. The woman, a sorceress named Madoushi, lashes out in rage, accusing Sakura of summoning Clow Reed, the legendary creator of the Clow Cards.
As the battle intensifies, Sakura discovers that her friends have been captured, and Syaoran Li is seized while trying to shield Tomoyo. Sakura narrowly escapes with Kero and Tomoyo Daidouji, only to find the book has vanished. [Kero] reveals that he knows Madoushi—she was once a fortune teller who lost customers when Clow’s predictions proved more accurate. Their rivalry drove her into the clutches of another dimension, and she remains unaware that she herself is a spirit. Sakura realizes the well pictured on the book cover is another gateway to Madoushi’s prison.
Determined, Sakura ventures to the well and encounters Yelan Li, who breaks the shield around the well to allow Sakura and Kero entry. In the ensuing confrontation, Madoushi weaponizes the memories and powers of Sakura’s friends to escape her trap, yet she is startled by the modern-day cityscape of Hong Kong. Pursuing her, Sakura and Kero follow, but Madoushi captures Sakura and locks her in a flooded skyscraper, using her clothes to threaten a fatal drowning. With the Arrow Card, Sakura escapes and faces Madoushi again, learning to empathize with the sorceress and confronting the truth that Clow is already gone. Madoushi dissolves into water and passes on, releasing Sakura’s friends in the process. Although Toya and Yukito have no memory of the events, Sakura tells Tomoyo and Kero that they may need to return to Hong Kong someday.
