In 1919, 17-year-old schoolgirl Yu Gwan-sun (Ko Ah-sung) is thrown in jail. But Yu isn’t just any girl; she’s a fierce, independence fighter and a leading figure of the March 1st Independence Movement. This is the story of her captivity in Seodaemun Prison in Japan-ruled Seoul, where she and other women are forced to live in the squalor of a 100-square-foot prison cell. Days of torture and deprivation can’t strip her dignity, and undaunted, Yu urges and inspires the female inmates of Prison Cell #8 never to lose hope, no matter how great the afflictions thrust upon them.