This paper reports the excavation of Lee Ik-sang’s Japanese novel “The Half-length Figure of Room 3,” which was mentioned as ‘the debut work’ in Lee Ik-sang’s retrospective but has not been discovered so far. Providing empirical information related to this novel, this paper also looks into the characteristics of the novel as a research object. Particularly, it seems rich in research potential to examine Lee Ik-sang’s nationalist aspects rather than much-discussed socialist aspects, considering his statement that he wrote “The Half-length Figure of Room 3” based on his real experiences participating in the independence movement in Tokyo and visiting the independence activist fellow in a Japanese prison. As a result of the investigation, the actual event that became the model for the novel was the second independence movement on November 5, 1921 after the 2.8 student movement in 1919, which was initiated by the Association of Choseon Students in Tokyo to petition the Washington Conference for Choseon’s independence. Although the name of Lee Ik-sang is not found in the declaration or the list of instigators, it became more likely through the novel that Lee Ik-sang participated in the movement. In addition, considering that Lee Ik-sang worked as an editor of Hakjigwang, and that people close to Lee Ik-sang, such as Kim Jun-yeon and Park Seok-yoon, were major executives of the association, Lee Ik-sang is believed to have been well aware of the association’s preparation for the independence movement. The latter half of “The Half-length Figure of Room 3” contains the process of the narrator’s moving from the entrance of the Tokyo prison to the meeting room to visit his colleague and observation of the surroundings. This part of the novel has side that reminds of Nakanishi Inosuke’s novels set in Choseon, because both of Lee and Nakanishi wrote a story about a foreigner entering prison in the country of residence, presented Koreans as “futei-senjin(disturbing Korean)” as the main characters, published their works around the same time, and even have a lot of history of interacting with each other. However, while Nakanishi’s novels exposed the inevitable limit of Japanese’s vision observing Choseon, even though the writer tried to express a sympathetic gaze and a sense o f solidarity towards “futei-senjin,” Lee Ik-sang’s novel is noteworthy that it made “futei-senjin” himself the subject of gaze by describing the Japanese space and characters observed by Korean.