Admiral Lee Sun-shin designs and builds the 'Turtle Ships' in preparation of the Japanese invasion during the Injin War. He is promoted after his victories, but due to his expanding influence and increased popularity in military circles, the king comes to fear him and has him imprisoned. A year later, the Japanese navy attempts another invasion and the king is required to enter the prison and beg the admiral's assistance.

After the Japanese Invasion of Korea in 1592, Iljimae, a master of the interlaced sword method, heads to Japan to find the national treasure, the Cheonryongsword, which was robbed by the Japanese pirate Kuroda. Around this time, there were two more men looking for Kuroda, one of them was Ma-cheol, a one-armed swordsman who lost his left arm due to Kuroda's trick, and the other was Kuroda's henchman Okamodo, who lost his newlywed wife and even lost his own eyes. This is Yoshiyama, the swordsman who lost his mind. At first, the three knights, who met by chance, were wary of each other for their own goals, but were captured by Kuroda's persistent pursuit. In the end, after a bloody fight, they succeed in revenge, and Iljimae returns home with the recovered Cheonryongsword.

In 1581, the monk Seo-san predicts that the Japanese are planning an invasion of Korea. He goes to the king, suggesting that the kingdom build a stronger army, but he is thrown out of court. He begins training three pupils in martial arts, but rumors reach the king that Seo-san is training an army. The king sends his soldiers to have the monk arrested

When King Myeong-jong dies, his son takes the throne and the old king's concubines are expelled. One of the concubines becomes pregnant. Believing that only she knows the true father, she claims the unborn child is the former kings and has a claim to the throne. The enemies of the new king, ignoring facts, decide to support her claim and threaten to start a civil war.

General Wang-gun marches on the capitol and overthrows the usurper Ku-jin who had slain the last king of the Shilla Dynasty. Wang-gun becomes king and begins a new era in Korean History--the Koryo Dynasty.

The son of a Chosun Dynasty general, Kim Du-han finds himself orphaned when the dynasty ends and the Japanese colonize Korea in the early 1900's. He sets out to build a resistance army in this historical drama.

General Kwak, despite having retired from military service, organizes a small army to resist the onslaught of an invasion from Japan in the early Chosun Dynasty