This paper examines how a founder’s entrepreneurial identity (formed initially by the founder) was dynamically reinforced and developed in conjunction with strategic decisions, ultimately exerting a sustained influence across generations. This case study focuses on Hirose Paper Mfg. Co., Ltd., a manufacturer of wet-laid nonwoven fabrics primarily targeting the industrial functional paper market. In the case company, the founder established the entrepreneurial identity before the company’s founding. This identity aligned with a business system centered on horizontal collaboration with technology trading companies and a core technology strategy built upon that system. Subsequent generations inherited the strong connection between identity and strategy, established by the founder. It ultimately played a foundational role in enabling later generations to attain a global niche leadership position in the microfiltration/ultrafiltration membrane substrate market for filtration applications in the liquid treatment sector.