It’s Cardcaptor Sakura episode 3, and Sakura is suddenly faced with the second of the four elemental cards – a card for which she’ll need more than just the cards she’s collected to capture.
Sakura takes a class trip to the aquarium, which includes them viewing the penguin exhibit. However, a weird whirlpool suddenly occurs in the middle of the pool, trapping one of the workers and a penguin, forcing Toya, who is working there part time, to jump into the water to free them.
Kero thinks that it is the working of the Watery card, one of the four elemental, and most powerful, of the Clow Cards. The problem is that Watery is too powerful for the three cards she’s captured so far – even the Windy card, the first elemental card, which Sakura kept when she opened the Clow book.
On the way home from school the next day, Sakura loses control while rollerblading because she’s thinking about the Watery Card, and nearly runs into Yukito, who asks Sakura if she wants to go out somewhere with him, which she happily accepts.
On their date, Yukito takes Sakura to…the aquarium. While there, the mysterious whirlpool shows up again in a giant water tank that extends up through a diner they’re eating in, almost drowning everyone until Yukito is able to break a door, allowing the water to drain. During the aftermath, Yukito mentions something about not being able to get snow cones while there, which gives Sakura an idea.
That night, Tomoyo, Sakura, and Kero sneak into the aquarium, where Sakura lures Watery out of the water tank and has it chase her through the building until she lures it into the freezer, which Tomoyo had been tasked to find. There she uses windy to freeze Watery, allowing Sakura to easily return it to a card.
This episode helped show that capturing Clow Cards doesn’t necessarily half to be about, or even sometimes can’t be about, overpowering it with a stronger Clow Card, like we’ve seen in the two previous episodes. In this case, Sakura had to take advantage of the Card’s weak point – in this case the fact that Watery freezes – in order to capture it.
Of course, this gives Sakura a pretty potent arsenal to capture all the rest of the clow cards from now on, having two of the four elemental cards in her deck.