The battle began when the independence armies led by Hong Beom-do and Choi Jin-dong attacked and destroyed the Japanese military police border post.

The reason for this overwhelming victory was the independence army's heightened morale, the commander's foresight, and excellent operational planning.

[4] On June 4, 1920, a platoon of the Hong Beom-do and Choi Jin- dong units of the Independence Army attacked Samdunja, Wolsingang, Hwaryong - hyeon, Bukgan-do.

Departing from , they crossed the Duman River and attacked and destroyed a 1-platoon-sized Japanese military police border post stationed in Gangyang-dong , Jongseong -gun, Hamgyeongbuk-do.

Accordingly, Lieutenant Jiro Nihimi, commander of the Japanese Army's Namyang Garrison, led one company and attacked them without permission.

The clever guidance operation of Platoon Commander Yi Hwa-il, who displayed outstanding skills in this battle, is highly regarded.

The leadership of the Korean Northern Army Command, including Hong Beom-do and Choi Jin-dong, judged that the best way to confront a superior enemy with inferior troops was to occupy key operational points.

In the early morning of June 7, when the Yaskawa unit entered the empty Ansan village 300 meters ahead, the lurking independence fighters opened fire all at once.

The Yaskawa unit joined forces with the Nihimi Company to fight, but suffered significant damage due to adverse geographical conditions and a surprise attack.

When the Yaskawa unit arrived in the western part of the Goryeo region, it suffered a crushing defeat after coming under fierce fire from a small number of independence forces ambushed in the northern and northeastern highlands.

[3] From the morning of June 7, the Hong Beom-do and Choi Jin-dong reorganized the Korean Northern Army Command forces of 1,300 in preparation for the Japanese attack.

The main force of the Japanese army was ordered to fire all at once when it entered the siege where the independence army was lurking, and ordered Director of Military Affairs Lee Won (李園) to lead the headquarters troops and the remaining companies, supply ammunition, etc., and secure a retreat route in case of emergency.

The reason for this overwhelming victory was the independence army's heightened morale, the commander's foresight, and an excellent operational plan that took advantage of geographical locations.