When Hamtaro hears that Laura and Kana are attending a Halloween party at Roberto's, he thinks that it's a "Hamoween" party. He tells the ham-hams all about and finds about Halloween, although none of the ham-hams are too sure of the details of it. Then Elder Ham and Auntie Viv give them some advice and Cappy and Panda make costumes for all of the ham-hams. After receiving a mysterious invitation, they head into a forest, where they find themselves at the mercy of Auntie Viv and Elder Ham, who have dressed up in scary costumes to terrorize them. Meanwhile, Kana and Laura create their costumes in a hurry and also decide to dress up Brandy. When they arrive late for the party, Roberto plays a trick on them by dressing up his puppy Samba as goblin. This gives them a scare, but Brandy's costum