Misako Nishiguchi, nicknamed "Mi-san," is one of the twelve students in Hisako Ōishi's first-grade class in 1928, located in a rural village. By 1933, as a sixth-grader, she is married. While her classmates record future aspirations, her specific dreams are not detailed.

In 1941, during Japan's wartime period, Misako is noted among the former students who have entered adulthood, married, though her husband's status is unspecified. On April 4, 1946, her daughter Katsuko enrolls in Ōishi's class, demonstrating Misako's ongoing connection to the teacher. Katsuko later appears in class alongside children of other original students.

As an adult, Misako attends a reunion for Ōishi with surviving classmates Sanae, Kotsuru, and Masuno. During this event, she accompanies Ōishi to visit the graves of deceased classmates Tadashi, Takeichi, and Nita, who died during the war, highlighting enduring bonds and shared loss. Katsuko uses her mother's maiden name in class records, with no elaboration on Misako's marital or family circumstances.