The purpose of this study was to examine the process how Japanese mothers working at private companies as a generalist balance their work and family life, and how they adapt their working style after returning from their first maternity leave. Semi-structured interviews were conducted with 20 working mothers who worked at 9 private companies in the Tokyo metropolitan area. The interview data were qualitatively analyzed according to the Modified Grounded Theory Approach (M-GTA). A hypothetical model was constructed with 6 category groups, 23 categories, 1 subcategory, and 81 concepts based on the data.
 The major findings were as follows. Working mothers face work-family conflict when they return to work from maternity leave, and when they want to develop their careers. In order to manage their work and family tasks, working mothers develop and utilize as many as 40 practical and psychological coping strategies. In the process of doing this, working mothers acquire skills such as multitasking, time management, working in team, etc. When work-family conflict is resolved through these skills, a doublerole lifestyle under restrictive time limitations is normalized for working mothers. Finally, working mothers come to feel work-family enrichment which can be described as “the fruits of the working mother life.” These findings may be used for deeper understandings of the dynamics involved from the perspective of industrial organizational psychology.