Nobita travels to the future to show his beloved grandma his bride, but adult Nobita has fled his own wedding.

In the turbulent last days of the Edo period, Kawai Tsugunosuke, a Japanese samurai serving the Makino clan of Nagaoka, dreamt of independence from the restraints of vassalship. Despite his progressive views and his desire for his estate to remain neutral during the Boshin Civil War, he was bound by loyalty and duty to the clan and was compelled to choose sides.

Teacher Kawashima Haru takes a position on a remote island off the coast of Hokkaido, where she takes charge of six students. However, she is later forced to leave after an accident occurs. 20 years later, Haru learns that one of her former students has committed a crime, and eventually returns to the island once more.