We analyze the genealogical structure of large Japanese firms, with pa
rticular emphasis on the relationship between parent firms and spinoff
subsidiaries. The wide use of spinoffs and subsidiaries in Japan prov
ides for flexible organizational mutations that appear to facilitate i
ncreased competitiveness and offer the opportunity to obtain benefits
through a deliberate separation of core competencies. We discuss a con
ceptual framework for the spinoff arrangement, the results of an explo
ratory empirical analysis of the relationship between parent and subsi
diary organizations, and implications of the use of this organizationa
l structure. We suggest the importance of a consideration of the gneal
ogical aspects of large Japanese firms in strategy research.