Much of the writing research on generation 1.5 students has focused on college students in educational contexts, especially either freshman composition or college ESL writing classes. Relatively little is known about them in K-12 settings, especially high-school students, despite their growing presence in these settings. In addition, there is a lack of understanding of these students' literacy experiences beyond the classroom. This paper discusses a case study that examined one Korean high school student's composing practices outside of school. The findings revealed several significant characteristics in her voluntary composing practices: the diversity and richness of her involvement with multiple literacies; her swift and constant movement among multiple genres, contexts, and languages; the public nature of her composing (sharing her writing with peers); her primary focus on L1 writing activities; and her construction of a writerly identity. In presenting her story, the paper attempts to build understanding of out-of-school writing as experienced by students with immigrant backgrounds.