Japanese and American company structures differ in key areas such as salary, promotion, and employee commitment. In Japan, salary increases with age and tenure rather than performance. Employees are expected to stay with one company their entire career through assignments in different roles. In contrast, American salaries and promotions are based on individual performance and careers progress within specific functions or departments with employees typically changing jobs or companies several times. While lifelong commitment builds strong company culture in Japan, it limits flexibility, while frequent job changes in the US bring new ideas but undermine loyalty and culture.