Genre: Fantasy

While cleaning the house, Sakura finds two dormant Clow Cards, The Wood and The Rain. But while running an errand for her father, the two cards activate creating a jungle inside the house. Sakura uses The Watery to capture The Rain card and The Wood yields on her own. Sakura gets the hard-earned lesson that a card is not fully subdued until she signs her name on it.

Sakura's class is on a field trip to the aquarium. During the penguin show, something catches the trainer's leg and a penguin and pulls them into the water, but they are saved by Sakura's brother, Toya, who is working part-time there. At school, Tomoyo gives Sakura and Cerberus mobile phones and on the way home, Sakura bumps into Yukito who invites her on a casual "date" which is at a cafe where Yukito knew Toya was working. While they are eating, The Watery breaks the glass of the aquarium causing a flood. For the first time Sakura has to formulate a plan to capture a card, rather than jumping into battle and attacking with Windy. Using her wits and an unintentional clue from Yukito, she lures Watery into a freezer to immobilizes and capture it.

Tomoyo meets Cerberus after she discovers Sakura's secret and gets a full explanation of the lost Clow Cards and Sakura's designation as Cardcaptor. Cerberus gets given the nickname "Kero-chan" that will stick for the rest of the series. The next day, the students find the school's desks and equipment in large piles. Kero believes it was the work of the card and forces Sakura to go to school at night where she confronts The Shadow. Using the Windy card's binding ability, Sakura is able to capture the Shadow card. Sakura finally accepts her role as a Cardcaptor because of Tomoyo's support.