Seven letters written by Korean independence fighter Na Seok-ju that shed light on his plans to destroy Japan-run companies in protest of Japan’s 1910-45 colonial rule are on display at the National Museum of Korea, from Friday to Oct. 9.

Shown to the public for the first time, the letters, written to fellow activists in 1925, discussed how Na found it more viable to bomb Joseon Siksan Bank and the Oriental Development Company in central Seoul among other Japanese state-run businesses.

On Dec. 28, 1926, Na attempted to carry out his bombing plan, but the bombs failed. A gun battle with Japanese police officers ensued in which Na shot himself. He was taken to a hospital where he died. He was 34.

The letters reveal Na’s deep commitment to the operation. The letters also implored others to join him in the cause and to keep the bombing plan secret. The letters were addressed to three independence activists, including Kim Gu.

Na was posthumously awarded the Presidential Medal of Honor in 1962.

“The letters detail the plans Na had in mind and demonstrate his conviction,” said Kim Jae-hong, director of the National Museum of Korea.

“We hope to pay tribute to independence fighters and rediscover what Liberation Day means for us Koreans,” Kim added, referring to the upcoming day of remembrance on Aug. 15.