Hamtaro has recently been experiencing an unusual dream featuring a distressed princess hamster in need of assistance. The dream lingers with him even during his waking hours. One winter day, Laura informs Hamtaro that her family plans to visit her father's hometown. Excitedly sharing this news with his friends, Maxwell pulls out an old book about hamster history, which reveals a "homeland" for hamsters called the "Hamja Kingdom". The Ham-Hams build a sandcastle, recite a spell, and are magically transported to the kingdom. Upon arrival, they are greeted by the Mini-Hams, King Hamja, and Mo-Hams in a lively parade filled with music and dance. However, their joyous atmosphere is abruptly interrupted by the arrival of the malevolent Sabakunya and her monstrous sheep, Mee Mee. Panic-stricken, the Ham-Hams retreat underground, where they learn of Sabakunya's plan to force Princess Shera into marriage and seize control of the kingdom. Hamtaro realizes that Princess Shera is the same hamster from his dream and decides to free her. With the Ham-Hams by his side, they delve into the danger-filled castle, evading Sabakunya's minions until Hamtaro is separated from his friends.