This paper will focus on the image of house in Cynthia Kadohata’s The Floating World (1989), which tells the story of a Japanese American family that has often been kept out of house. The protagonist, 12-year-old Olivia, a Sansei (third-generation) Japanese American girl, grows up in 1950s America with her parents, grandmother, and younger brothers, moving in the country in search of a stable job and house. Later, her family finally acquires a permanent house to live in. However, just as Olivia’s consciousness frequently leads her out of the house and she later begins to move out her house and live on her own, this work depicts her ambiguous feeling of wanting to move out again, despite having been allowed into the house. While several previous studies have focused on the protagonist and mentioned the ambiguity of her belonging and identity, they do not specifically highlight the characters’ ambivalent feeling toward house. This paper will try to capture the image of house as seen in the eyes of each of the characters, not only the protagonist, but also her grandmother and parents, and will show the meanings of being inside and outside the house. It will also discuss how these issues prompt Olivia to reconsider the concept of inside / outside of the house. Regarding the feelings about house, the Issei (first-generation) grandmother and Nisei (second-generation) parents have conflicting attitudes: while they long to enter, they do not always have positive feelings about doing so due to the issues of gender roles and ethnicity. Olivia, a third-generation girl who has long sought to remain in her house, is also described as having ambiguous feelings toward house. One reason for this seems to be the overlap between the image of her Arkansas house and that of the concentration camps built during World War Ⅱ. Olivia’s voluntary departure from her house is closely tied to Isseis’ and Niseis’ feelings toward the house and solidarity with people belonging outside of the house. While maintaining her connection to the inside of the house, Olivia also acquires a space outside the house in which she can feel safe and comfortable. Such a situation implies that the boundaries that distinguish between inside and outside the house have become blurred.