An 11-year-old girl named Laura, along with her parents, her dog Brandy and hamster Hamtaro, moves into their new house. Hamtaro gets out of his cage and goes outside, where he meets a hamster named Oxnard. They fall underground, meeting up with Boss who shows them his house. He says he needs help telling a girl how he feels. Meanwhile, Laura meets Kana and buys a journal that she updates every night.