Monolingual-ness is a mystery in Japan. Despite much has been invested to teach and learn English, most L1 Japanese people seem to think that they are monolingual (Terasawa, 2015). Furthermore, it is fair to say that policies imposed to make all Japanese learn to use English seems to be rejected at the local level as grand narratives often are; for example, the policy of English-medium teaching in all the nation's high school English classes is largely ignored. Although learning English conversation from native speakers of English remains popular, the Japanese who actually use foreign languages is a small minority. It appears that the Japanese accept monolingualism as normative, yet there is little situated understanding of monolingualism in Japan. I conducted repeated, long, and mostly unstructured interviews with well-educated male and female native Japanese speakers who professed they were monolingual despite having received years of school English education. In addition to general life histories, the participants' narratives included their experiences regarding languages; Japanese, English, and others. The participants also reflected why and in what ways they were "monolingual." The study analyzed the fully transcribed stories as a mass of rhizome (Deleuze & Guattari, 1980), a non-centralized structure like ginger roots or types of fungi. Narrated life stories appear to be presenting a linear chronology of events, therefore, the narratives tend to be analyzed as such. However, the analysis in the present study shows that each story represents a rhizomatic growth of the participant' s world, in which events and situations from different time and places transcended and intricately affected one another. Specifically, the study located some salient life's events, or rhizomatic nodes, for instance, relocation and job changes, which affected the participant's languages as well as relationship. Finally, the presentation will contemplate how the perceived "monolingualism" was constructed in the participants' rhizomes.