When he was six, he was adopted by Kim Pyŏnggi, a distant relative who had lost his son and was desperate to secure the continuation of his family lineage.

At the age of 22, Kim took the national civil service exam, and was ranked "Changwon Kŭpchae" (level 6) (usually it took about ten years to achieve this status).

To avoid the possible negative impacts of the internal political conflicts that could result on his adopted son, Kim Byung-gi retired from his holding.

At the time, Heungseon Daewongun, who had implemented policies to avoid contact with the West for ten years, lost political power.

Although trade with Europeans began and foreign policies were adopted, the situation worsened, and Kim meddled in the internal conflicts in the palace.

Kim advocated for more open policies to the West so that Korea might adopt Western European ideals, knowledge, and technology, thereby securing its existence in the rapidly modernizing world of the 19th century.

After arriving in Tokyo, he met with various influential Japanese politicians during his stay, and was sponsored by Fukuzawa Yukichi to study at Keio University from February to August 1882.

Kim felt that, in order to ensure survival when China was in decline, Korea would have to borrow Japanese help to modernize itself, and that the only solution to the situation was to introduce a new political force to wipe out the present dominant party.

The Gaehwapa activists continued to meet at Kim's private house and discuss the ongoing events concerning East Asia and the international politics.

In a feast offered by Kim for the members of the Min Yeong-ik political faction, several Japanese government officials were present, including Inoue and several of the Gaehwapa activists.

Shimamura explained that the Japanese still support the movement, and that the internal conflicts and misunderstandings contributed to the ill relationship for Kim with Inoue.

It consisted of the assassinations of certain political figures, and creating a major chaos on the day of the reception for the founding of "Ujeongchongguk" (우정총국; 郵政總局), or Office for International Postal Service.

The truths behind the Gapsin Coup incident were leaked to Queen Min (posthumously known as Empress Myeongseong), and the plans of the Gaehwapa threatened her political rights.

Hong Jong-u, who had travelled to Japan in 1893 to assassinate Kim Okgyun and Park Yeong-hyo, another reform-minded Korean, learned of the voyage and managed to obtain passage to China on the same vessel.

Fukuzawa Yukichi led a memorial service in Japan in Kim's honor, and erected a gravestone for him at the Aoyama Cemetery in Tokyo.