The Informal Structure of Senpai (Seniors), Kohai (Juniors), and Doki (Peers) in Japanese Organizations

Definition

In Japanese organizations, those who join earlier are called senpai (seniors), those who join later are kohai (juniors), and those who join in the same year are called doki (peers). The relationships among senpai, kohai, and doki function as an informal hierarchical structure working in tandem with the formal job-based organizational hierarchy. These relationships are deeply rooted in unique Japanese concepts, such as ba, the Confucian cultural tradition that influenced the formation of Japanese society, and the historical background of large organizations in modern Japan. Specifically, the seamless school-to-work transition due to the batch hiring of new graduates every April creates a similar hierarchical structure to that of senpai, kohai, and dokyusei (classmates) in schools. The balance between the formal job-based hierarchy and informal seniority-based (senpai–kohai–doki) hierarchy has been the base of the stable and harmonious organizational characteristics that enable effective knowledge management and efficient operations but poses challenges in adapting to new environments.

1. Introduction

From the 1950s to the 1980s, the Japanese economy enjoyed miraculous economic growth, dominating the global market with high-quality, appropriately priced “made in Japan” products [1,2]. Among the factors contributing to its success are Japan’s unique employment practices and organizational structure, which allowed for teamwork and harmony among highly committed employees as well as flexibility in the business environment [3,4,5,6]. For example, traditional Japanese employment practices are often referred to as membership-based employment, in which employees are hired as members of the organization with no restrictions on job duties, working hours, or location [7]. Because they are members of the organization, their job security is guaranteed until mandatory retirement age, resulting in lifelong employment [8,9]. Other unique characteristics of Japanese organizations include heavy reliance on the batch hiring of fresh school graduates, employee development through on-the-job training (OJT), job rotation and employee transfer practices across departments and sections, seniority-based compensation and promotion, enterprise-based unions, a teamwork orientation, and consensus-based decision making [10,11].

Behind the distinctive characteristics of Japanese organizations is the duality between formal job-based and informal seniority-based hierarchies among organizational members [12]. The formal job-based hierarchy represents organizational structure based on job titles and the system of responsibility, authority, and chain of command. The informal seniority-based hierarchy is based on the year of entry into the organization among members. This informal seniority-based structure often synchronizes with the formal job-based structure to maintain order and harmony in the organization to create a family-like or village-like atmosphere.

2. Informal Seniority-Based Structure

In Japanese organizations, based on the year of entry into the organization, those who entered earlier are called senpai (seniors), those who entered later are kohai (juniors), and those in the same year are called doki (peers) [12]. The relationships among senpai, kohai, and doki are considered an informal institution, “a set of rules, compliance procedures and moral and ethical behavioral norms designed to constrain the behavior of individuals in the interests of maximizing the wealth or utility of the principals” [13] (p. 201), which are likely to persist over time [14]. In Japanese, “senpai” literally means a member who came earlier and “kohai” means a member who came later.” “Doki” literally means a member who came at the same time. Senpai goes ahead of kohai and kohai follows or obeys senpai in the same goal or rail, whereas doki go together. These distinctions go beyond mere times of arrival and encompass a cultural understanding in which the senpai is seen as leading or guiding and the kohai as following or obeying, often in the same path or with the same destination. The senpai–kohai–doki relationships are the foundation for understanding the social and organizational dynamics in Japanese society [12].

The senpai–kohai dynamic in Japanese organizations is deeply embedded in cultural expectations of mutual support and respect [15]. This dynamic creates a culture in which senpai members are expected to take care of their kohai, and kohai members, in turn, look up to and respect their senpai [16,17,18]. The kohai members also return the favor for the guidance and support they received from their senpai by doing the same for their kohai, as their senpai, so that the relationship of reciprocity continues not only in the specific generations but is passed on to the next generations in organizations. The continuous cycle of favors and reciprocation between levels and generations in the organization reinforces a sense of community and belonging, contributing to the overall stability and harmonious atmospheres in the organization.

The characteristics of the doki relationship are influenced not only by the fact that they join the organization at the same time, especially in April, immediately after graduation, but also by the fact that they are sandwiched between senpai and kohai members. Whereas the senpai–kohai relationship is vertical and involves some degree of formality, using polite language (kohai members use polite language to show respect to senpai members) in communication, the doki relationship is horizontal, so its communication is more casual and friendly. Because of these characteristics, doki members in the organization are likely to develop their shared identity as doki groups who join in the same year [19], which is similar to classmates in school, such as the students of a certain class (e.g., class of 2025).

The relationships among senpai, kohai, and doki explained above contribute to the maintenance of order and harmony in the organization with a complex web of relationships. These complex relationships include direct senpai–kohai interactions in the same job or department, horizontal doki relationships in or across departments, and diagonal senpai–kohai relationships that span departments. The interplay among these types of relationships contributes to the unique organizational culture found in many Japanese organizations. The stable and harmonious organizational characteristics make nonverbal communication efficient and reduce the cost of written or explicit communication (e.g., documentation). Members of Japanese organizations are analogous to family or community members, creating the flexibility of organizing thorough internal mobility without laying off employees. The informal seniority-based hierarchy in Japanese organizations also contributes to effective knowledge sharing and creation, which have been a source of their competitive advantage globally [20].

3. Key Concepts to Understanding Seniority-Based Hierarchy in Japan

3.1. “Ba” or Place as the Foundation of Social Hierarchy

The concept of “ba”, or place, is a key concept to understanding Japan’s social structure in general and the informal hierarchy in Japanese organizations in particular [21]. According to Nakane [21], “attribute” and ba can be used to explain the formation of social groups. Attribute refers to specific characteristics such as bloodline or occupational status. Nakane argued that in Western societies and India, social groups are primarily formed based on attribute, as exemplified by the caste system in India. In contrast, ba refers to affiliations with specific organizations or communities, such as companies or villages. In Japan, where ba is predominant, social positioning is primarily determined by the ba to which one belongs, rather than by individual “attributes” such as occupation.

Figure 1 shows how informal hierarchy is developed in ba. According to Nakane [21], the concept of ba assumes that individuals who arrive earlier at a place occupy a higher status in the social hierarchy. That is, those who come first are at the top of the pecking order. Those who come later are placed below them. As a result, a hierarchy of ranks is established by order of arrival. This hierarchy is supported by the Japanese long-term employment system and the regular hiring of a new batch of graduates every April [21]. Such hierarchical dynamics are not merely superficial distinctions but are central to shaping interactions and organizational culture in Japanese institutions.

3.2. “Amae” as the Foundation of Human Relationships in Japanese Society

Doi [22] suggested that the senpai–kohai relationship, like many other interpersonal relationships in Japan, contains the concept of “amae”—the idea of indulgent dependency in Japanese relationships. This concept illuminates the subtle interdependence and reciprocal obligations that characterize these relationships, highlighting the unique blend of respect, care, and authority inherent in the senpai–kohai dynamic. This is in contrast to Western society and its individualistic culture. In such societies, people are relatively independent rather than interdependent, and jobs, positions, and authorities in organizations are designed so that members can independently perform their duties. In Japan, with a relatively collectivistic culture, interdependencies in organizational operations are essential, and the interactions among members, especially those between senpai and kohai, play an important role in the activities. In this way, the system involving amae influences professional and social interactions, often dictating the flow of communication, mentorship, and respect in the organizational context.

3.3. The Concept of “Ie” or Family in Japan

The concept of ie, which can be interpreted as “family” or “household,” also influences the nature of Japanese organizations. According to Kuwayama [23], ie is the basic unit in Japanese society, and large groups, such as Japanese organizations and even the entire nation, are considered structural extensions of ie. The nuance of ie is different from that of family or household in Western society such that the members are not limited to kinship but are extended to other individuals. Thus, ie assumes the pseudo-relationship of kinship and it can be easily extended to large groups, such as modern Japanese organizations [24]. Therefore, Japanese organizations can be understood as an extension of ie, and the employment patterns and management in Japanese organizations are similar to those for ie. For example, the head of the company is analogous to a father in the family or household, and employees are the children under the parents’ authority [25]. Therefore, the Confucian traditions in the family relationship (e.g., parents and children and older and younger brothers and sisters) apply to interpersonal relationships, such as senpai–kohai–doki relationships in the organization. This is consistent with “(family) membership-based employment”.

4. Confucianism as a Cultural Foundation

The senpai–kohai–doki relationships are deeply rooted in Confucianism, which influences the structuring of hierarchical relationships in the family and social contexts in East Asian countries, such as China, Korea, and Japan. Confucianism prescribes that those born earlier are expected to love and care for those born later, establishing a basic social ethic [26]. Therefore, the older family members (parents, older brothers, and older sisters) are followed by the younger family members (children, younger brothers, and younger sisters). It is a social norm that those born earlier love and take care of those born later. Confucianism has also shaped non-family relationships in society such that younger people respect older people and older people impart their knowledge to younger people. Linguistically, older people are addressed with polite language, reflecting a cultural emphasis on respect for age [15,27]. On the other hand, peers and younger individuals are often addressed in a more casual manner. This distinction in language use is a fundamental aspect of Japanese social interactions [28].

Showing humility to elders, offering one’s seat to the elderly, and buying drinks for juniors are examples of these conventions that reflect a broader cultural value system that prioritizes respect, care, and deference in hierarchical structures [28]. From these norms, an informal hierarchical power structure is created between senpai and kohai (i.e., senpai is superior to kohai, and kohai must follow the orders of senpai). In an informal power relationship, senpai has the informal right to make kohai obey him/her and senpai has the informal obligation to take care of kohai. This relationship is not enforced by formal rules but is deeply rooted in the social fabric and reflects a complex interplay among respect, duty, and authority [18,29]. Similar informal seniority-based structure and power relationships exist in the Confucian Asian regions (e.g., China and Korea) [15]. However, the degree to which such a society-level informal institution also exists in work organizations may differ across these East Asian countries [30], and the following unique historical background in Japan strengthened the link between society-level and organization-level structures.

5. Historical Background of Japanese Large Organizations

The historical background of Japanese organizations, especially large Japanese corporations, also contributes to the development of the senpai–kohai–doki relationships in organizations. As discussed earlier, Japanese organizations heavily rely on hiring fresh graduates, nurturing them over the following decades, and provide them with long-term job security until the mandatory retirement age. This kind of employment system was established when Japan entered a period of “rapid economic growth”, after World War II [8,31]. In that period, Japanese organizations grew rapidly and needed to secure a stable supply of new employees for smooth operations. To make this possible, Japanese organizations focused on batch hiring and long-term training [31,32]. As a result, this practice, took root as a social system to immediately accept young school graduates as new employees of organizations, forming a school-to-work transition mechanism unique in Japan, which is discussed later [32].

6. Similarities with the Japanese School System

The senpai–kohai–doki hierarchy in large Japanese organizations closely mirrors the structure of Japanese schools, where relationships based on age and time of entry are deeply ingrained [15,27]. In Japan, students enter school every April. As discussed earlier about how ba works in Japan, the hierarchy of student communities is updated in a way that the senpai–kohai relationship is carried forward [15,21]. Dokyusei students are sandwiched in between senpai and kohai (the word “dokyusei” in schools has the similar meaning as “doki” in Japanese organizations) [16,21]. This annual cycle fosters a distinct pecking order, influenced by Confucian norms, in which senpai, kohai, and dokyusei occupy specific roles in the school community.

Large schools shuffle classmates each year, creating varied peer interactions while reinforcing vertical (senpai–kohai) and horizontal (dokyusei) relationships. Relationships among senpai, kohai, and dokyusei are further cultivated through participation in extracurricular activities such as athletic and cultural club activities, which are a staple of Japanese school culture [27,33]. Because there is almost no grade skipping, the student body is stable [34], consisting of senpai, kohai, and dokyusei. Transfer students who join a class or grade consisting of such stable relationships from the outside are the exception.

One key reason for the similarities between the structure of work organizations and that of schools in Japan is related to Japan’s seamless school-to-work transition, particularly through batch hiring every April. As Figure 2 shows, students who graduate from schools become employees virtually overnight, moving from student status on March 31 to employee status on April 1 [35,36]. This smooth school-to-work transition facilitates the transfer of hierarchical characteristics from schools to work organizations, especially in traditional large Japanese organizations. Specifically, the senpai–kohai–dokyusei relationships and the periodic lateral movement of same-year students across the classes in large schools are transferred to work organizations that contain virtual and lateral member moves [33]. The mid-career hires are analogous to transfer students who join a school year consisting of already established stable student relationships [37].

7. The Balance Between Formal and Informal Structure

In traditional large Japanese organizations, the formal job-based position ranks, which are typically based on the combination of ability-based and seniority-based evaluations and promotions, and the informal senpai–kohai–doki hierarchical order based on the timing of entry, have been well balanced and harmonized. Especially in younger generations in an organization, positions and compensation levels remain close among doki members, and they are promoted in the formal job-based hierarchy in almost the same way and receive pay raises of almost the same amount. For older generations, the pyramid-shaped chain of command organizational structure makes fewer managerial positions available for promotion, as illustrated in Figure 2, and not every doki member can be promoted in the same way. However, the job-based grades determined through the assessment of competencies or abilities can continue to be promoted, and the same pace of promotions and pay raises can be somewhat maintained among doki members to keep the balance between formal job-based and informal seniority-based structure [10]. This balanced dual structure has been integral to the functioning of Japanese organizations.

Because of this subtle balance between formal job-based hierarchy and informal senpai–kohai–doki relationships, conflicts between ranks of members are kept minimal, contributing to the stable and harmonious organizational culture. In other words, the formal hierarchy generally aligns with the informal hierarchy, as senior members hold higher positions and receive greater remuneration, peers occupy the same rank, and junior members remain in lower ranks, inherently minimizing the likelihood of conflicts among members. The continuous cycle of favors and reciprocation between levels of the formal and informal hierarchies reinforces a sense of community and belonging, contributing to the organization’s overall stability and cohesiveness with a family-like or village-like atmosphere [16,18]. As a result, members of the organization have high levels of commitment and loyalty, and informal mentoring and OJT naturally occur between senpai and kohai in the same workplace [17,18]. Communication, knowledge sharing, and knowledge creation among organizational members are also efficient and effective [20,38].

The Tension Between Formal and Informal Structures

Although the informal senpai–kohai–doki relationships in Japanese organizations contribute to stable and harmonious organizational characteristics, they have been an obstacle to implementing various practices that are needed to adjust to the changing environment, and introducing radical practices might cause tension between the informal seniority-based structure and the formal job-based structure. For example, mid-career hiring from outside the organization has been considered the exception rather than the norm. To maintain order and harmony, the careful consideration of where mid-career hires fall in the existing senpai–kohai–doki relationships in the organization has been necessary. Additionally, because of the Japanese male-dominated business society in Japan, the senpai–kohai–doki relationships in Japanese organizations has also been dominated by male regular employees.

Therefore, it is difficult for non-regular employees (e.g., contract, temporary, and part-time workers), female employees, and foreign employees to be fully accommodated into the informal relationships [12,39]. The active hiring of mid-career employees who have knowledge, skills, and abilities that are necessary for the organization to adjust to the new environment and increasing diversity by hiring and promoting female and foreign employees as well as various non-regular employees [40,41] might pose a threat to the stable and harmonious hierarchical order consisting of senpai, kohai, and doki members.

Introducing merit-based or performance-based compensation and promotion practices in Japanese organizations is also challenging because these practices create inconsistency and tension between formal and informal hierarchies. High-performing and competent kohai may overtake their senpai to receive higher salaries and promotions more quickly. As a result, kohai may be placed in higher ranks than their senpai and may become their senpai’s supervisors. In addition, there will be differences in salary and speed of promotion among doki members. That is, the younger and lower-ranked employees in the informal hierarchy can pass the senpai and be promoted more quickly if they are competent. In such situations, the senpai–kohai mentoring becomes less effective and malicious envy may occur that harms the senpai–kohai–doki relationships, disrupting order and harmony in the organization and making the organization unstable, which may also affect organizational performance.

8. Conclusions

The informal seniority-based hierarchical structure consisting of senpai, kohai, and doki has been the basis of Japanese organizations that enable them to function smoothly with stability and harmony. However, as the world’s societies change, globalization advances, and populations and generations change, these informal hierarchical structures in Japanese organizations are likely to change as well. One possible direction is the weakening of the informal hierarchy’s power in organizational functioning and the decoupling of formal and informal structures. That is, formal structures would become more substantial in the management and operation of the organization. For example, newly established Japanese start-ups do not follow traditional Japanese employment practices, and young people can take on important positions [42]. For this reason, people in newly created organizations may be relatively indifferent to the senpai–kohai–doki relationships. Multinational enterprises operating in Japan may also bring employment practices and organizational structures from their home countries that do not rely on the informal structure of Japanese society. Additionally, employment in Japanese multinational enterprises is becoming more unstable than before due to changes in international comparative advantage/disadvantage and the expansion, contraction, and withdrawal of investment, which makes the job-based structure and mid-career hiring more common among those organizations [43]. Furthermore, gender equality has been gradually promoted in Japan, and the number of female workers in Japan has increased by more than 7 million over the past 40 years [44]. Women may play an important role in changing Japan’s male-dominated business society, including the senpai–kohai–doki relationships. Nonetheless, informal hierarchical structures, which are deeply rooted in Japanese history, culture, and Confucianism, would remain influential in traditional Japanese organizations, even in the future.