Understanding Joint Work and Identification of an Author under Japanese Copyright Act

Japan’s content industry, spanning film, animation, music, and literature, is internationally recognized for its scale and creativity. For companies entering or expanding in this market, a clear understanding of the structure of Japan’s copyright regime is essential to manage risk and capture business opportunities. Although the basic architecture of copyright law overlaps with other jurisdictions, Japan has distinctive rules that can materially affect outcomes, particularly in collaborative creation and large-scale projects such as films.

This article focuses on two practice-oriented themes under the Copyright Act of Japan: the legal treatment of joint work when multiple creators are involved, and the identification of an author for cinematographic works, including the allocation of moral rights. It also outlines the basic rules on the duration of copyright protection, which directly affects the valuation and management of content assets. The aim is to provide executives and in-house counsel engaged with Japan’s content industries with a practical framework for structuring transactions and avoiding disputes.​

Japanese Joint Work: Rights Attribution and Exercise in Collaborative Creations

In practice, it’s common for multiple people to collaborate on a single work. In these cases, ‘joint work’ applies, and Japanese law has specific rules for how these rights are managed.

Definition of “Joint Work” Under Japanese Copyright Law

Under Article 2, Paragraph 1, Item 12 of the Japanese Copyright Act, “Joint Work” is defined as “a work created by two or more persons whose contributions to the work cannot be separated so as to allow each part of the work to be used independently.” This definition has two requirements: first, there must be joint involvement in the creative process itself, and second, the individual contributions must be inseparable at the level of the finished work.​

Providing ideas, supervision, or general assistance does not, by itself, make a person a joint author; the person must engage in the creative act that shapes the protectable expression. A typical joint work would be a piece of music co-composed by several people, where it is not practically or conceptually possible to distinguish who created which specific musical elements. By contrast, combinations such as a novel and its illustrations, where each component can be exploited independently, are treated as “composite works,” and each author, in principle, exercises rights separately in their own contribution.

The Principle of Unanimous Consent in the Exercise of Rights

Where copyright is jointly owned, the exercise of that right is subject to a strict unanimity rule intended to protect each co-owner. Article 65, paragraph 2 of the Japanese Copyright Act provides that “a joint copyright may not be exercised without the unanimous agreement of all the co-owners”, and “exercise” covers both authorizing third parties and using the work oneself.​

As a result, a single co-owner may not unilaterally decide to publish the work, upload it to a website, or grant a license to another company without the consent of the others. This framework seeks to prevent situations where one co-owner’s unilateral use prejudices the economic or reputational interests of others.

Prohibition of Unjustly Refusing Consent

If the unanimity requirement is applied without qualification, the work may be effectively locked and unusable if one co-owner refuses to cooperate. To mitigate this risk, Article 65, paragraph 3 of the Copyright Act of Japan provides that a co-owner may not obstruct the formation of consent “without just cause.”​

“Just cause” is not defined in the statute and is interpreted by the courts based on the specific facts, including the parties’ conduct and the overall course of dealings. For example, in the Osaka District Court’s judgment of August 27, 1992 (the “Quiet Flame” case), refusal of consent was treated as justifiable where another co-owner had advanced license negotiations unilaterally without sufficient consultation. Conversely, where a co-owner continues to withhold consent without a rational basis, the other co-owners may bring an action seeking a court judgment that functions as a substitute for that party’s manifestation of intent.

Confronting Infringement and Disposal of Share of Joint Copyright

The unanimity principle also applies to the disposition of jointly owned copyright, such as transfers to third parties or the establishment of pledge. Article 65, paragraph 1 of the Copyright Act of Japan requires the consent of all co-owners for these acts, and the same restriction on unjustified refusal of consent applies.​

The position is different, however, where a third party infringes joint work. Under Article 117 of the Copyright Act of Japan, each co-owner may individually seek an injunction to stop the infringing conduct, and the law does not require unanimous consent in light of the need for prompt and effective relief. As to monetary relief, each co-owner is generally entitled to claim damages only in proportion to that person’s share of joint copyright, so the allocation of shares should be addressed clearly at the contracting stage whenever possible.​

In sum, Japan’s framework for jointly owned copyright is built on a baseline of collective decision-making, tempered by a prohibition on arbitrary refusals of consent and practical mechanisms for enforcement against third-party infringers. Companies that engage in joint development, co-production, or other collaborative creative projects should reflect these statutory rules in their contracts, including detailed provisions on use of the work, licensing procedures, and dispute-resolution mechanisms among co-owners.​

Identifying the Copyright Holder: The Unique Legal Framework for Cinematographic Works Under Japanese Copyright Act

As a default rule, the author who creates a work originally acquires the economic rights, but cinematographic works are treated differently under the Copyright Act of Japan.

Special Provisions on Copyright of Films

Article 29, paragraph 1 of the Copyright Act of Japan provides that, if the author of a cinematographic work has promised the producer of the cinematographic work that the author will participate in its production, the copyright to that cinematographic work belongs to the producer of the cinematographic work. “Producer of a cinematographic work” is defined in Article 2, paragraph 1, item 10 as the person that does the conceptualizing and has the responsibility in the production of a cinematographic work, which in practice usually means the production company or studio that handles financing and overall management.​

The core legal feature of Article 29 is that it establishes original attribution, not a mere statutory presumption of transfer. Copyright does not first arise in the hands of individual creators, such as the director, and then transfer; instead, it originates in the film producer from the moment the work comes into existence. This approach is grounded in the reality that cinematographic works require substantial capital and coordinated contributions from many people, and that centralizing rights in the producer facilitates licensing, distribution, and exploitation across different media.​

Who Is the “Author” of a Film Under Japanese Copyright Act?

The fact that the copyright belongs to the film producer does not mean that there is no “author” in the sense used by the Copyright Act of Japan. Article 16 defines the author of a cinematographic work as the person that makes a creative contribution to the overall shaping of the work through responsibility for its production, direction, staging, filming, art direction, etc., and this category typically includes the director.​

By contrast, the author of the original novel, the screenwriter, and the composer of the music are authors of their respective works but are not treated as authors of the cinematographic work itself. Their contributions are component literary work, script, or musical composition—that are incorporated into the film, but they do not themselves shape the overall structure of the finished cinematographic work in the sense required by Article 16.

The Location of Moral Rights Under Japanese Copyright Act

Although Article 29 allocates economic rights in cinematographic works to film producers, moral rights are treated separately under the Copyright Act of Japan. Economic rights, such as the rights of reproduction, distribution, and transmission to the public, are proprietary rights categorized as “copyrights,” whereas moral rights—such as the right to make a work public, the right of attribution, and the right to integrity—are understood to be inherent in the individual author.​

These moral rights remain with the film’s author, such as the director, even where the copyright in the cinematographic work vests originally in the film producer. Accordingly, film producers must exercise caution to avoid infringing upon the moral rights of authors, such as directors, when making modifications to a film.

The relationship between the director and the production company in a typical film can be summarized as follows.

Exceptions to Copyright Rules for Films and Practical Considerations

Although the basic rule under Article 29, paragraph 1 is that the film producer holds the copyright in cinematographic works, the Copyright Act of Japan sets out important exceptions. Businesses must determine which of these frameworks applies to each film they handle.​

Exception 1: Wroks made in the course of Duty

The first major exception arises where the cinematographic work qualifies as a work made in the course of duty under Article 15 of the Copyright Act of Japan. Under this provision, for a work that an employee of a corporation or other employers (hereinafter in this Article such a corporation or other employers are referred to as a “corporation, etc.”) makes in the course of duty at the initiative of the corporation, etc., and that the corporation, etc. makes public as a work of its own authorship, the author is the corporation, etc., so long as it is not stipulated otherwise in a contract, in employment rules, or elsewhere at the time the work is made.

In a film context, this may occur where a production company produces a film internally through a director who is an employee. In such a case, the corporation is not merely the copyright holder under Article 29 but is instead treated as the author, which means both economic rights and moral rights that would otherwise vest in the director are attributed to the company itself.

Exception 2: Films for Broadcasting

The second exception concerns cinematographic works produced exclusively for broadcasting, such as television programs made by broadcasters. Article 29, paragraph 2 of the Copyright Act of Japan provides that, for such works, certain rights belong to that broadcaster as the producer of the cinematographic work—namely, the right to broadcast, the right to transmit, and the right to reproduce the work for broadcasting and distribute those copies to other broadcasters.​

Other rights, including the right to exhibit the work in theaters or to exploit it in formats such as DVDs or other packaged media, generally remain with the author, such as the director, unless the parties agree otherwise by contract. This structure reflects the business model of broadcasting, where the core economic interest lies in the ability to transmit the work.

Challenges in Practice as Seen from Court Cases

Despite the existence of these statutory provisions, determining rights in older films—particularly those produced under previous versions of the Copyright Act of Japan—can be complex. A notable example is the Intellectual Property High Court judgment of June 17, 2010 (Heisei 21 (Ne) 10050), which addressed the attribution of copyright in a film produced under the old law.

In that case, the court recognized the director as one of the authors but held that copyright had been implicitly transferred to the film company and granted the company’s request for an injunction against infringement. At the same time, the court dismissed the claim for damages, finding no negligence on the part of the defendant in light of the ongoing academic debate and the resulting uncertainty over authorship and rights allocation under the former regime. The decision illustrates that, even with statutory rules in place, interpretation can remain unsettled, and it highlights the need for thorough due diligence when acquiring or exploiting historic film libraries.

Overall, the Copyright Act of Japan sets up a layered system for allocating rights in cinematographic works, depending on the production background and intended use: theatrical films under Article 29, a work made in the course of duty under Article 15, and broadcasting works under Article 29, paragraph 2. For contract negotiations and M&A transactions involving film rights, correctly classifying the work into one of these categories is the starting point for any legal and commercial analysis.​

Copyright Protection Duration: The Temporal Limits of Rights in Japan

Copyright protection is inherently time-limited, and once the statutory period expires, works enter the public domain and, in principle, become freely usable.

General Principle of Protection Duration

Under Article 51, paragraph 2 of the Copyright Act of Japan, the general rule is that copyright subsists for 70 years after the death of the author. This period was extended from 50 years to 70 years by an amendment that took effect on December 30, 2018, but protection for works whose term had already expired at that time was not revived.​

Exceptions to the Principle

The Act sets out several important exceptions to the “70 years after death” rule, depending on the type of work and how it is published.​

• Joint works: For works with multiple authors, the protection period runs for 70 years from the death of the last surviving co-author (Article 51, paragraph 2 of the Copyright Act of Japan).​
• Anonymous or pseudonymous works: Where a work is published without identifying the author or under a pen name, the term is 70 years from the date of publication, unless the author’s true name becomes known during that period, in which case the general rule of 70 years after death applies (Article 52).​
•  Works whose authorship is attributed to a corporation or other organization: Works published under the name of a corporation or other organization, including works made in the course of duty, are protected for 70 years from the date of publication (Article 53).​
• Cinematographic works: Cinematographic works are likewise protected for 70 years from the date of publication (Article 54), aligning their term with that of works published in the name of corporations.​

Article 57 of the Copyright Act of Japan provides that the starting point for the calculation is the year after the year in which the author dies or the work is made public or created. For example, if an author dies in 2020, the 70-year period begins on January 1, 2021, and expires on December 31, 2090.​

The main statutory terms can be summarized as follows.

While the term for an individual’s work is tied to the author’s death, the term for works where a corporation is typically the right holder such as film works is anchored to the objectively verifiable date of publication. Because corporations do not “die” in the same way as natural persons, using publication as the starting point promotes legal certainty and transactional predictability in managing copyright portfolios. For companies, it is therefore critical to analyze the nature of each asset and identify which set of term rules apply before making strategic decisions about exploitation, enforcement, or divestment.​

Conclusion

Japan’s copyright regime incorporates distinctive rules that are particularly relevant for collaborative and industrial-scale creative activities, and these rules are increasingly important in cross-border transactions. The strict unanimity principle for joint work, and the special allocation of cinematographic copyright to producers are representative examples. These provisions aim to balance the protection of creators’ rights with the development of the industry.

For companies operating in or entering Japan’s content market, understanding these frameworks is not merely a compliance exercise; it is a strategic requirement for maximizing the value of intellectual property and avoiding disputes over ownership and scope of rights. Monolith Law Office has extensive experience advising domestic and international clients on these issues, including drafting joint work contracts, conducting IP due diligence in media-related M&A, and resolving complex copyright disputes, and can provide support that integrates Japanese legal requirements with global business practices.

If you have any inquiries regarding Japanese copyright law, please do not hesitate to contact us.