Gaksital Hyung-rae and the Dokkaebi is a Shim Hyung-rae children's fantasy comedy that parodies Gaksital (각시탈), the classic Korean masked hero from the manhwa series by Huh Young-man. The film reimagines Shim Hyung-rae as the legendary masked vigilante, mixing martial arts, comedy, fantasy, and Korean goblin folklore.

Hyung-rae, the three musketeers, and Sol are students of Master Ttaengcho. While gather wild greens in the mountains they witness a sword battle where Yoshimura Genjo displays amazing swordmanship. Upon hearing this Ttaengcho tells the students of his three greatest disciples in the past: Mu-cho of Korea, Peng Jia of China, and Yoshimura Genjo of Japan. All three harbor ambition to conquer the martial world, but are kept in check by the others. However, Mu-cho of Korea has now disappeared along with the power of the Golden Mask.

A bumbling but good-hearted hero, Hyung-rae, becomes entangled in a conspiracy involving foreign agents, corrupt officials, and rival martial artists during Korea’s historical era. After coming across an injured warrior who warns of Japanese spies, Hyung-rae finds himself caught between competing factions seeking power. As assassins, warriors, and schemers collide, Hyung-rae and his companions stumble through a series of comedic misadventures, ultimately becoming unlikely heroes in a chaotic battle of loyalty, deception, and martial arts spectacle.

Sol-i and Song-i head to Hanyang with the blueprint for a cannon invented by their father. On the way, they meet Japanese pirates and get captured, but Baek Du-geon appears and defeats the pirates and saves Sol-i and Song-i. Sol-i and Song-i arrive in Hanyang and hand over the blueprint to Hong Cham-pan, and Baek Du-gun and the three insect musketeers cause a commotion. Hong Cham-pan, who was handed the blueprint, works with the snake demon and tries to sell the blueprint to a Japanese spy (Miyamoto). Based on the popular segment 'Drumbeat from the Border' from KBS's Humor No. 1 at the time.

Hyung-rae plays a byeoldang (‘Byeoldang’ refers to a detached residence in a noble household, and by extension to an idle, freeloading young nobleman attached to it. Basically a useless aristocratic hanger-on.) who becomes entangled in a supernatural adventure involving a powerful dragon pearl, a flying “messenger from hell,” and martial arts battles blending folklore and slapstick humor.