The film mainly follows the famous 1597 Battle of Myeongryang during the Japanese invasion of Korea 1592-1598, where the iconic Joseon admiral Yi Sun-sin managed to destroy a total of 133 Japanese warships with only 13 ships remaining in his command. The battle, which took place in the Myeongryang Strait off the southwest coast of the Korean Peninsula, is considered one of the greatest victories of Yi.

When Jo Gang-Ja attended high school, she was notorious for fighting. She gave birth to her daughter A-Ran in her late teens and became more responsible. Her daughter A-Ran is now a high school student, but A-Ran is bullied at school. Jo Gang-Ja decides to go back to high school to protect her daughter. Jo Gang-Ja becomes a high school student again.

His only friend called him 'the man from nowhere'... Taesik, a former special agent becomes a loner after losing his wife in a miserable accident and lives a bitter life running a pawnshop. He only has a few customers and a friend named Somi, a little girl next door. As Taesik spends more and more time with Somi, he gets attached to her. Then Somi is kidnapped by a gang, and as Taesik tries to save Somi by becoming deeply associated with the gang his mysterious past is revealed...