Decoding Copyright Similarity in Japan: The "Direct Perception of Essential Expressive Features" Test

Japanese Attorney at Law - Bengoshi L.L.

• 8 min read

In the realm of copyright law, determining whether one work is unlawfully similar to another is a critical and often complex task. Japanese copyright jurisprudence has developed a distinct standard for this assessment, famously known as the test of whether one can "directly perceive the essential expressive features" (表現上の本質的な特徴を直接感得できる - hyōgen-jō no honshitsu-teki na tokuchō o chokusetsu kanto dekiru) of an earlier work within a later one. This standard is pivotal in Japanese copyright infringement cases, serving as the judiciary's primary tool for gauging illicit similarity.

The Genesis: The Parody Montage Photo Case

The conceptual roots of the "direct perception" test can be traced back to a significant Supreme Court decision on March 28, 1980, commonly referred to as the Parody Montage Photo case (第一次上告審). This case, while primarily concerned with an author's moral rights (specifically, the right of integrity), laid the groundwork for the broader application of this standard.

The dispute involved a photographer whose original photograph of skiers creating tracks on a snowy mountainside was altered by a graphic designer. The designer incorporated a large image of a snow tire into the scene, juxtaposing it with the ski tracks to create a satirical commentary, and published this as a black-and-white montage. The Supreme Court, in addressing the alleged infringement of the photographer's moral right to maintain the integrity of his work, stated that while using another's work as material for one's own creation is not inherently impermissible, such use without the original author's consent is only allowable if it is done "in a manner that does not make the essential features of the expression format of the other's copyrighted work perceivable as such."

This ruling implied that if the core expressive elements of the original work were no longer directly discernible in the altered work, then the latter might be considered a new, independent creation, or at least a use that doesn't improperly exploit the original's protected expression in a way that violates the author's moral rights.

While the Parody Montage case introduced the "direct perception" concept in the context of moral rights, its definitive establishment as a cornerstone for copyright infringement, particularly concerning adaptation rights (翻案権 - hon'an-ken), came with the Supreme Court's landmark judgment in the Esashi Oiwake case on June 28, 2001.

This case involved a well-known Japanese folk song, "Esashi Oiwake." The plaintiff, who held the copyright in a particular musical arrangement and lyrical version of this traditional song, sued a television broadcaster. The broadcaster had produced a program featuring a narration that, according to the plaintiff, was an unauthorized adaptation of the song's prologue lyrics, accompanied by new imagery.

The Supreme Court provided a crucial definition of what constitutes an "adaptation" under Japanese copyright law. It held that an adaptation refers to the act of creating another work by relying on an existing work and, while maintaining the identity of its "essential expressive features," adding modifications, additions, or changes to the concrete expression, thereby creatively expressing new thoughts or feelings, in such a way that a person who encounters it can "directly perceive the essential expressive features of the existing work."

Critically, the Court reasoned that if the defendant's work is altered to such an extent that one can no longer directly perceive the essential expressive features of the plaintiff's original work, then the defendant's work is considered a separate and distinct creation, falling outside the scope of an adaptation of the original. In such instances, it would not constitute an infringement of the adaptation right. In the Esashi Oiwake case itself, the Court found that the TV narration, when considered with its accompanying visuals and overall context, did not allow for the direct perception of the essential expressive features of the plaintiff's song prologue, thus negating the claim of adaptation right infringement.

This judgment cemented the "direct perception of essential expressive features" test as the central criterion for assessing similarity in the context of derivative works and, by extension, other forms of copyright use.

Deconstructing "Essential Expressive Features"

The efficacy of the "direct perception" test hinges on a clear understanding of what constitutes "essential expressive features." Japanese courts and legal scholarship have clarified that this term is not all-encompassing but refers specifically to the creative aspects of the expression itself. Two fundamental principles of copyright law underpin this understanding:

  1. The Idea-Expression Dichotomy: Japanese copyright law, like that of many other jurisdictions, protects only the expression of thoughts or feelings, not the underlying ideas, facts, emotions, or themes themselves. Therefore, for infringement to occur, the commonality between two works must lie in their protectable expressions. If only abstract ideas or general concepts are shared, the "essential expressive features" of the original work are not deemed to have been taken, even if the subsequent work was inspired by the original.
  2. Creative vs. Non-Creative Expression: Furthermore, not all elements of an expression are considered "essential expressive features." The features must be part of the creative contribution of the author. Elements that are commonplace, standard, dictated by the subject matter, or "arikitari" (ありふれた表現 - ordinary or trite) do not qualify for protection under this standard. For example, if a particular way of depicting a common object is standard or one of only a few ways to express that idea, that depiction, even if part of the overall expression, would not be an "essential expressive feature" whose taking would lead to infringement. The creativity lies in the author's personal, unique way of expressing an idea beyond these commonplace elements.

Thus, the "direct perception of essential expressive features" test effectively asks whether the defendant's work has incorporated those specific parts of the plaintiff's work that are both expressive (not mere ideas) and creative (not merely commonplace).

Broad Applicability of the Test

The significance of the "direct perception of essential expressive features" test extends beyond adaptation rights. It has been consistently applied by Japanese courts as a general standard for determining whether an existing copyrighted work has been "used" in a manner that implicates any of the exclusive rights granted to a copyright holder, as well as their moral rights.

Numerous lower court decisions have explicitly invoked this standard when assessing claims of infringement of:

  • Reproduction Rights (複製権 - fukusei-ken): Determining if a work has been copied to such an extent that the original's essential expressive features are directly perceivable in the copy.
  • Moral Rights (著作者人格権 - chosakusha jinkaku-ken): Particularly the right to integrity (同一性保持権 - dōitsu-sei hoji-ken), where unauthorized alterations are judged based on whether they damage the direct perception of the work's original essential expressive features, and the right to be named (氏名表示権 - shimei hyōji-ken), where displaying one's name on a work not sufficiently similar to one's original work would not be an infringement.

This consistent application underscores the test's role as a fundamental principle in Japanese copyright infringement analysis, providing a unified framework for assessing the illicit taking of protected expression across different contexts of use. It's worth noting that the phrasing evolved slightly from the Parody Montage case's "essential features of the expression format" (表現形式上の本質的な特徴) to the Esashi Oiwake case's more direct "essential expressive features" (表現上の本質的な特徴), a refinement that has become the prevailing standard.

The Test and the Concept of "Similarity" (Ruijisei)

While the term "similarity" (類似性 - ruijisei) is widely used in academic discussions and legal commentaries to describe the required nexus between an original work and an allegedly infringing work, it is important to note that the Japanese Copyright Act itself does not prominently feature "similarity" as an explicit criterion for infringing primary exclusive rights like reproduction or adaptation. This contrasts with other intellectual property statutes in Japan, such as the Design Act or Trademark Act, which explicitly refer to "similar" designs or marks.

In practice, the judicial standard of "directly perceiving essential expressive features" serves as the functional equivalent of what legal scholars mean by "similarity" in the copyright context. It is the test through which courts determine if a subsequent work is close enough to an original copyrighted work to be considered an infringement. In recent years, there has been an increasing trend in court judgments to also use the term "similarity" (ruijisei) when discussing this aspect of infringement, aligning judicial language more closely with academic discourse.

Theoretical Underpinnings: A Brief Overview

The interpretation of the "direct perception of essential features" test is not without academic debate in Japan. One major theoretical discussion revolves around its precise scope.

  • Creative Expression Monism (創作的表現一元論 - sōsaku-teki hyōgen ichigenron): This view posits that the "direct perception of essential features" is essentially synonymous with finding a "commonality of creative expression." If the creative expression of the original work is found in the defendant's work, then similarity (and likely infringement, barring defenses) is established.
  • Overall Comparison Theory / Independent Significance of Direct Perception Test (全体比較論 / 直接感得性独自基準説 - zentai hikakuron / chokusetsu kantoku-sei dokuji kijun-setsu): This alternative perspective suggests that even if some commonality in creative expression exists, the "direct perception" test might have an independent role. It could involve a more holistic comparison, considering the entirety of both works, including their differences. Under this view, if the original work's creative elements are so transformed or "fade" into the new work's overall distinctiveness, then the essential features might not be "directly perceivable," potentially leading to a finding of non-infringement. This latter approach sometimes draws parallels with concepts like "freie Benutzung" (free use) in older German copyright law, where a new independent work using an existing one could be permissible if the original's characteristics receded against the new creation's individuality.

These debates highlight the nuanced doctrinal considerations involved in applying what appears to be a straightforward test.

For those familiar with U.S. copyright law, the Japanese "direct perception of essential expressive features" test invites comparison with the "substantial similarity" standard. While both serve the ultimate purpose of determining whether an impermissible level of copying has occurred, there are differences in formulation and, potentially, in application.

The Japanese test, with its explicit focus on "essential expressive features," inherently emphasizes the need to filter out non-protectable elements (ideas, facts, commonplace expressions) as a core part of identifying what is being "directly perceived." The Esashi Oiwake case, for instance, clarified that if the commonality lies only in non-expressive parts or non-creative expressions, there is no adaptation.

U.S. law also distinguishes ideas from expression and requires copying of protected expression. The "substantial similarity" analysis often involves a two-part test (e.g., extrinsic/intrinsic) and also seeks to filter out unprotectable elements. However, the precise methodologies and the way courts articulate the filtering process can vary. The Japanese "chokusetsu kanto" test provides a relatively unified articulation that directly integrates the concepts of expression and creativity into the perception-based standard. A detailed comparative analysis would be extensive, but the Japanese formulation offers a distinct lens through which to view the complex issue of copyright similarity.

Conclusion

The standard of "directly perceiving essential expressive features" is a critical judicial doctrine in Japanese copyright law. Originating in the context of moral rights and later firmly established for copyright infringement through landmark Supreme Court decisions, this test provides the framework for assessing whether a subsequent work has illicitly appropriated the protected core of an earlier copyrighted work. It demands a careful distinction between unprotectable ideas and protectable expression, and between creative contributions and commonplace elements. While subject to ongoing academic discussion and nuanced application, its central role in determining copyright infringement and defining the scope of an author's rights in Japan remains undisputed. Understanding this test is essential for anyone navigating copyright issues involving Japanese works.