Right now, the General Union is handling cases at Japanese tech companies where well-established workplace practices have come under threat. These include businesses pushing for return-to-office mandates after years of remote work, eliminating flexible scheduling, and cutting bonuses and other forms of compensation.
Japanese labour law protects workers in two significant ways here. First, there’s the principle of established workplace practices (労使慣行, roudou kankou), protected through decades of court precedents, which can give unwritten customs the same legal weight as written rules. Then there’s Article 8 of the Labour Contract Law, which prevents employers from unilaterally changing documented working conditions.
But having these legal protections is only half the battle. While the courts have established strong precedents, as an individual, pursuing these rights can be prohibitively difficult. Taking an employer to court is expensive, time-consuming, and potentially career-damaging. This is where collective action through unions becomes essential. Unions provide both the legal expertise and collective leverage needed to uphold these rights.
By understanding their legal rights and organizing collectively, developers can effectively protect and even improve their workplace conditions in this critical moment.
How the courts protect you
A series of landmark cases in Japan created robust protections for workplace customs, also known as established employment practices. But what qualifies as an established employment practice?
Case 1: Post-Retirement Employment Practice (RECOGNISED)
東豊観光事件 (Toho Kanko), Osaka District Court 28, June 1990
In this order by the court, the company’s work regulations stated that the forced retirement age (定年, teinen) was 55. In practice, however, the company repeatedly kept employees on after they had reached this age. This custom continued for six years (1984–1990), during which 7 out of 8 employees who reached the age of 55 were retained. When the company terminated the 55 year-old plaintiff, citing the official retirement rule, the plaintiff sued for confirmation of employment status.
The court stated that the practice of continued employment after 55 had become an established workplace custom. That custom overrode the written regulations, despite its relatively short period of practice, because it had been consistently applied to almost all employees who had reached the retirement age during that time.
Case 2: Extra Pay for Substitute Holidays (DENIED)
商大八戸の里ドライビングスクール事件 (Syodai Yae-no-sato Driving School), Osaka High Court 25 June, 1993, and upheld by Supreme Court 9 March, 1995
Employees claimed entitlement to extra pay when working on a substitute holiday. The company’s policy was that every other Monday was a day off. If that particular Monday fell on a national holiday, Tuesday would become the substitute day off (振替休日, furikae kyuujitsu). The question was whether working on these Tuesday substitute holidays entitled workers to extra holiday pay.
Although this practice had existed for 10 years, both the Osaka High Court, and the Supreme Court denied that it was an established workplace practice because the specific situation—working on a Tuesday substitute holiday—had only occurred 8–10 times during that period. This case demonstrates that frequency matters. Even when established over a lengthy period of time, if the actual instances of the practice are rare, it may not be considered established.
Case 3: Bonus Amount Practice (PARTIALLY RECOGNISED)
立命館事件 (Ritsumeikan), Kyoto District Court 29 March 2012 (appealed, outcome uncertain)
This case involved a bonus dispute. For 14 years, according to labour agreements (労働協約, roudou kyouyaku), the company had paid a bonus of 6.1 months’ salary plus 100,000 yen. However, there was no provision about bonuses in the company work rules (就業規則, shuugyou kisoku). When the employer announced the forthcoming bonus would be only 5.1 months’ salary, employees claimed the higher amount was an established practice.
The court made an interesting distinction:
- It ruled that the specific amount (6.1 months + 100,000 yen) was NOT an established practice because there had been negotiations each year before agreeing on the amount, even though the final amount had always been the same.
- However, it recognised that “at least 6 months’ salary” had become an established practice, because the employer’s initial offer had never been lower than 6 months throughout the 14-year period.
This case demonstrates the nuanced way courts examine whether a practice has created a legitimate expectation that can’t be unilaterally changed.
These examples show that determining what constitutes an established workplace practice isn’t a simple matter of time. Courts look at consistency, frequency, specificity, and whether both sides understood the practice to be binding—even if they didn’t write it down.
Other cases of interest
The courts’ protection of established practices has occasionally been implemented in surprising ways. Take a case from 1968 that went all the way to the Tokyo High Court. The issue? Whether railway workers could continue their long-standing practice of using the company bath at 4 p.m. and clocking out at 4:30. At first glance, it might seem trivial—why fight over a bathing schedule? But the court’s decision was significant: after 13 years of this practice, with management’s knowledge and acceptance, it had become a legally-protected workplace custom that couldn’t be unilaterally changed.
In the 1973 Shishido Shokai case (宍戸商会事件), the Tokyo District Court ruled that a company must pay severance to a voluntarily-resigned employee because consistent payment to other departing employees had established a binding workplace custom. The court classified these payments as deferred wages, confirming that consistent practices can create legal rights without written policies.
Even when ruling in employers’ favour, courts have reinforced the importance of established practices. The 1982 Daiwa Bank case (大和銀行事件) upheld the bank’s long-standing practice of paying bonuses only to those still employed on payment dates, ruling that workers who left before payment weren’t entitled to bonuses despite working during the calculation period.
These court precedents have established principles that apply universally across all industries. Whether a railway worker’s bathing schedule from the 1960s or solidifying employer rights, established employment practices are a real concept that can be parlayed into tech workers’ fight to maintain their working conditions.
What does the law say?
Article 8 of the Labour Contract Law also protects you against unilateral changes to working conditions.
So, what constitutes the “contents of a labour contract”? Does this only deal with working conditions that are specifically written into your employment contract?
According to General Union Chair Toshiaki Asari, “The idea that long-standing practices can become part of the employment contract and receive legal protection—even if they aren’t explicitly written—is well-established as a legal doctrine. Therefore, long-standing practices should also fall under the protections of Article 8 of the Labour Contract Law, just like written working conditions.”
This perspective is supported by a significant 1991 Supreme Court ruling in the Hitachi Musashi Factory case (日立製作所武蔵工場事件). When an employee refused to work overtime during a production issue, claiming the request was unreasonable, the court found that the company’s consistent practice of requiring overtime in specific situations had become an implied term of employment—even without documentation. Because this practice was long-standing and implicitly accepted by employees over time, the court upheld the company’s disciplinary action. Though the ruling was in the employer’s favor, it also established that workplace customs, through consistent application and mutual understanding, can become legally binding components of employment contracts.
Does this mean an employer can never change any working condition? The short answer is: they certainly can. This right of the employer to change working conditions is established in both Articles 9 and 10 of the Labour Contract Law. However, Article 9 also sets up a fundamental principle: employers cannot unilaterally change working conditions to workers’ disadvantage by modifying work rules without employee agreement.
- Properly communicated to workers
- Reasonable given the degree of disadvantage to workers
- Necessary for the business
- Appropriate in their revised content
- Preceded by proper negotiations with unions or worker representatives
This framework ensures that while employers can adapt to changing business needs, they cannot do so by simply imposing disadvantageous changes on workers without justification or prior consultation.
The reality of defending your rights
But what do these legal protections really mean in practice? Terms like disadvantages, reasonable, necessary, and appropriate sound reassuring on paper. Yet their practical meaning becomes far less clear when your employer suddenly demands you return to the office after five years of remote work, or changes how raises are calculated, or alters stock option arrangements.
Taking your employer to court is a long, expensive process that could take years to resolve, and that’s not only in the case of established employment practices. Even the seemingly clear prescriptions of the Labour Contract Law can only be enforced through court action.
In the meantime, you’re stuck working under the contested conditions, while potentially damaging both your career and wellbeing. And remember, if you want to negotiate with your employer about changes to workplace practices, they have no legal obligation to even meet with you. They can simply ignore your requests or refuse outright.
The power of collective action
Unlike individual workers, who can be ignored or denied the chance to meet with management, employers cannot legally refuse to negotiate with a labour union.
Unions offer multiple pathways for protecting workers’ rights and established employment practices. One key strategy is establishing prior consultation agreements (事前協議協定, jizen kyougi kyoutei), which require employers to inform and consult with the union before implementing changes to working conditions. By securing a seat at the table early, unions can influence decisions and propose alternatives before changes are implemented, rather than fighting them after the fact.
Through collective bargaining, unions can also convert established workplace practices into written agreements, giving them stronger protection than relying on court precedents alone. By codifying these customs in collective agreements, they become immune to unilateral changes by employers. This matters because collective agreements sit at the top of the workplace rules hierarchy, superseding both individual contracts and company work rules—they’re the gold standard in protecting workers’ rights.
True, an employer might still break a collective agreement, but unlike individual workers who can only turn to courts or government agencies, unions have multiple ways to respond. They can file complaints with the Labour Commission, as violating a collective agreement constitutes an unfair labour practice under the Trade Union Law. Most importantly, unions retain the right to take direct action through strikes and other collective measures—options simply not available to individual workers.
While some employers might still attempt to violate the law, most understand that directly confronting unions by targeting their members creates more problems than it’s worth. Remember, your right to labour union representation is enshrined both in the Trade Union Law and Article 28 of the Constitution, which states that “The right of workers to organise and to bargain and act collectively is guaranteed.”
Unions can also push beyond merely protecting existing rights, into negotiating improvements that particularly matter to tech workers—like expanded remote work options, clearer overtime compensation for project crunch times, training and skill development budgets, improved parental leave policies, and protections against excessive on-call rotations. Unions can also establish guidelines on emerging issues like AI implementation policies and the right to disconnect after working hours.
Conclusion
For developers, this situation presents a unique opportunity for collective action. Japan’s tech industry, worth nearly 22 trillion yen in domestic IT investments alone, mirrors the automotive industry of mid-20th century America—a wealthy, rapidly growing sector desperately in need of workers at all skill levels. Like the auto plants of Detroit, modern tech companies rely on a diverse workforce ranging from highly-paid specialists to entry-level developers.
This combination—a wealthy industry, a significant labour shortage, and the critical role tech workers play in company operations—creates unprecedented leverage for collective action. Just as auto workers used their position to secure better wages and working conditions in the 1950s and 1960s, tech workers today could wield similar influence. The cost of lost productivity in tech companies can run into millions of yen per day, giving organised workers significant bargaining power.
Moreover, unlike in traditional manufacturing where production delays might only affect future sales, many tech companies lose revenue immediately when work stops. By maintaining critical systems, supporting client operations, and keeping online services running, tech workers’ daily tasks directly impact their companies’ bottom lines. Even a small group of organised workers can effectively advocate for better conditions.
Through union membership, you combine legal protection with collective power—that is, you have both the law on your side and an active organisation working to protect your rights, with real mechanisms to enforce them.
