A 10-year-old girl named Laura, along with her parents, her dog Brandy and hamster Hamtaro, moves into their new house. After their arrival in the new house, Hamtaro gets out of his cage and goes outside, where he meets a hamster named Oxnard. Both Hamtaro and Oxnard fall underground, only to meet a hamster named Boss and his house. They go outside and sing a song for a female hamster named Bijou. However, after the dancing performance, Hamtaro notices Bijou winking at him, signaling her crush o
Nanmaru and the other students head to Marukami Village to search for the missing professor.
Emi keeps searching for the missing professor, while Nanmaru and the others return to Tokyo.
Nanmaru debuts as a lecturer, while Emi edges closer to the truth of the Tanabata Festival.
Nanmaru starts a new business venture and Sachiko, now in Tokyo, tries to stop Takashi.
While Sachiko tells Nanmaru about her past, trucks and airplanes vanish in Tokyo causing a frenzy.
Tokyo plunges into chaos as Nanmaru tries to rescue the kidnapped Aki, facing his own power.
Nanmaru and the others head to Marukami Village to stop Yoriyuki.
Tensions in the village reach a climax as Yoriyuki's true intentions are revealed.
Mount Marukami's summit binds all mysteries, urging Nanmaru and Sachiko to confront their destinies.