In recent years, university-based Japanese language teacher training programs have faced a range of complex challenges, including a mismatch between the practical competencies required in educational settings and existing curricula, the need to maintain professional expertise while responding to increasingly diverse educational demands, limitations in faculty and institutional resources, difficulties in securing sufficient practicum opportunities, the provision of career support after program completion, and the integration and effective use of educational technologies such as ICT. In addition, given that not all individuals who complete such programs pursue careers as Japanese language teachers, it has become increasingly important to consider training approaches that remain meaningful even for practicum students whose primary career paths lie outside the teaching profession. This paper examines a case study of a Japanese language education practice implemented at Yamaguchi Prefectural University, a university where Japanese language education is not offered as a primary major. Focusing on an initiative that includes online Japanese language instruction for children with foreign backgrounds, the study investigates the outcomes and challenges of an educational approach aimed at fostering civic-mindedness and developing generic competencies in a multicultural society. Data were collected through a questionnaire survey administered to practicum students, consisting of five-point Likert-scale self-assessment items and open-ended responses. The analysis was conducted from multiple perspectives, including practicum students’ attitudes toward the practice, foundational skills for working adults, awareness of multicultural coexistence, reflections gained through teaching practice, and changes in future career outlooks. The findings suggest that this educational practice has educational significance not only in terms of acquiring Japanese language teaching skills, but also in fostering attitudes necessary for engaging with others as members of a multicultural society and in cultivating generic competencies related to interpersonal support. At the same time, several issues were identified that warrant further consideration, including program management, the articulation between theory and practice, and the development of collaborative frameworks with partner schools.