Kim Chang-su (Jeon Chang-geun), who participated in the Donghak Movement, escapes to Manchuria after being chased by the Japanese army, finally making his way home. Angered by the assassination of Empress Myeong-seong, he murders a Japanese lieutenant and is sent to jail. He escapes from prison turns his focus on the democratic movement by teaching civilians and organizing Sinminheo (a democratic organization), even changing his name to 'Kim Gu.' After he is imprisoned again, he gets out on parole and goes to China, where he participates in establishing a provisional government from which he can direct the anti-Japanese struggle. Kim Gu goes on to play a part in Yun Bong-gil's deeds in Shanghai, the events at Hongkou Park, the encounter with Jiang Jish, and the establishment of the Korean National Army, and leads the struggle for Korea's independence with warm fraternal love and clear national spirit. When Korea is liberated in August 15, 1945, he returns back to his native land.
