Hamtaro: The Captive Princess (2002)

Hamtaro has been having a peculiar dream: a lovely princess hamster pleading for assistance. He shares this with his friends, and Maxwell consults a Ham-Ham sourcebook. The book describes Hamja Kingdom, a homeland for hamsters, accessible by building a sandcastle and reciting a specific spell. Following the instructions, the Ham-Hams are transported to the bustling kingdom. However, their arrival is interrupted by Sabakunya, a mischievous cat riding a giant sheep monster named Mee Mee, who begins destroying the town. They learn that Sabakunya has kidnapped Princess Shera, the King's daughter, and is forcing her into marriage on the Kingdom's Founding Day to seize control. Hamtaro realizes that Princess Shera is the very princess from his dreams.