Costume featured in episode:
42 Costume featured in Chapter:
20 and 21
The Prince Costume is worn exclusively by Sakura Kinomoto in the 42nd episode of the anime: Sakura and the Blacked Out School Arts Festival, and Chapters 20 and 21 of the manga, when there is a Festival of Arts at Tomoeda Elementary and Sakura and her friends put on a play based on "The Sleeping Beauty".
It was not originally meant to be used to capture a Clow Card, but Sakura nevertheless is wearing it when she seals the Light and Dark cards.