One night, the Nohara family were enjoying a pleasant dream, when suddenly a big fish appeared in their dreams and ate them. The next morning, Hiroshi read in the newspaper that everybody in another town had the same nightmare as him, but it seemed to have ended. But Hiroshi also heard the same dream from Misae, Shinnosuke, Himawari and even Shiro. They were surprised and thought if the same thing is happening in Kasukabe too. In kindergarten, on telling others about his nightmare, Shinnosuke was surprised to know that everybody too had the same dream. Then a mysterious girl named Saki was transferred to Futaba Kindergarten and joined Shinnosuke's class. Everyone in the class, including the rather inactive Bo-chan, were all excited and happy on seeing her. But Saki had a cold attitude and didn't get along well.

Crayon Shin-chan: Fast Asleep! Dreaming World Big Assault!

Bir gün Tropical-Rouge Pretty Cure, Karlar Ülkesi Shantia'dan muhteşem bir davet alır. Sharon'un yeni kraliçe olmasını kutlamak için bir tören düzenliyorlar. Hepsi karın ışıltılı dünyasına doğru yola çıkıyor. Deniz Kızı Krallığı'nın kraliçesi olmak isteyen Laura, kendisine güzel bir yüzük veren Sharon ile arkadaş olur. Ancak tam verdikleri sözü tutmaya karar verdikleri sırada gizemli bir canavar aniden ortaya çıkar ve herkesi krallığa kilitler. Tüm umutlar tükenmiş gibi göründüğünde, Heartcatch Pretty Cure ekibi acele eder ve hepsine motivasyon verir. Ve duyguları birleşince yüzük Kar Yürekli Yüzüğüne dönüşür...