In August Juche 19 (1930), he led one of the groups of the Korean Revolutionary Army organized by President Kim Il Sung to advance into the homeland and aroused broad people to the sacred war against the Japanese imperialists.

His group's dauntless military and political activities greatly astonished the enemy.

He was arrested by the Japanese police due to a renegade. The Japanese ruffians made every vicious attempt like mediaeval torture and threat and blackmail in a bid to bring him to his knees.

In an attempt to stay his influence in prison they locked him up in a dark isolation cell and put irons on his wrists and ankles so that the irons cut into his flesh whenever he made the slightest movement. But he did not stop his struggle in such harsh conditions.

He inspired the prisoners with confidence in victory, saying at the last moment of his life as follows:

"Kim Il Sung is my nephew. He is now leading a large revolutionary force in Manchuria, thrashing the Japanese swine. It will not be long before his army storms into the country. Wait in arms to greet them. Only when we fight can we expel the Japanese ruffians and liberate the country!"

On January 12, 1936 his heart stopped beating in a frosted cell.

Kim Il Sung in his reminiscences "With the Century" said:

If there was anything my uncle feared more than death, it must have been the betrayal of the faith which makes a man righteous and courageous and enables him to be the most dignified being in the world.