In this chapter, we examine the topic of organizational commitment. HRM practices are designed to maximize organizational integration, employee commitment, flexibility, and quality of work. Therefore, the concept of employee organizational commitment plays an important part in this field. First, this chapter reviews the meaning and types of organizational commitment, including their association with various employee behaviors and work performance. Next, we discuss Commitment-based HRM practices, with an overview of the components and philosophies. Then we discuss Japanese Commitment-based HRM practices and some new trends that affect commitment in Japan. The chapter concludes with a discussion of future challenges in managing employee commitment in Japan.