1919: 17 year-old schoolgirl Yu Gwan-sun (Ko Ah-sung) is thrown in jail. 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 feet prison cell. Days of torture and deprivation does not strip her dignity. Undaunted, Yu Gwan-sun urges and inspires the female inmates of Prison Cell #8 never to lose hope, no matter how great the afflictions thrust upon them.