Introduction

Determining similarity of designs, for example, of a registered design and another design, is often the most difficult and crucial matter of design infringement cases. Regarding the similarity of designs, Article 24(2) of the Japanese Design Act provides as follows:

Article 24(2): Whether a registered design is similar to another design must be determined based upon the aesthetic impression that the designs would create through the eye of their consumers. [Japanese Law Translation (https://www.japaneselawtranslation.go.jp/en/laws/view/4806)]

In infringement cases, under Article 24(2), the similarity of designs is considered by first identifying the composition and the essential part of the designs. They are then compared as a whole to determine whether they share a common aesthetic impression. In many infringement cases, the similarity of designs is determined by the commonality of the “essential part”, i.e. the part that most easily attracts the consumer’s attention. Therefore, identifying the essential part is the most crucial aspect for determining similarity.

As an example of how essential parts are identified and what judgments are made as a result in Japan, I would like to introduce the following recent court case.

Overview of the Case

On September 11, 2025, the Osaka High Court (Case No: R7 (Ne) 800) upheld the judgement of the Osaka District Court (Case No: R5 (Wa) 10125) which concerned the plaintiff’s design right for a “Container for liquid soap dispenser”. The plaintiff made the following claims against the defendant based on the allegation that the manufacturing, sale, etc. of the defendant’s product constitutes infringement of the plaintiff’s design right:

• an injunction against manufacturing, sale, etc. of the defendant’s product (Article 37(1) of the Design Act);
• disposal of the defendant’s product (Article 37(2) of the Design Act); and
• compensation for damages (Article 709 of the Civil Code).

Plaintiff’s Design Right (JP Reg. No.1707515)

Defendant’s Product

The plaintiff’s partial design has a magnet, depicted by a solid line on the backside of the container for mounting on a wall, with the area around the magnet and the pump, depicted by a dotted line, being disclaimed. Furthermore, not only the pump but also the lid is detachable, making it possible to transfer liquid soap from its original packaging into the container. Both the plaintiff’s design and the defendant’s product have the presence of a magnet on the back and a detachable lid in common. The plaintiff argued that, since the magnet is not visible in the normal use state when it is attached to a wall, consumers would not pay attention to it, and that the two designs are similar due to their same external shape, their same dimensions of the lid and container body, as well as their similar basic shape of the magnet (vertically elongated rectangle).[1]

Courts’ Decision

The Osaka District Court, at the first instance, ruled as follows:

• Method for determining the similarity of designs

Considering Article 24(2) of the Design Act, the determination of similarity should take into account the nature, purpose and manner of use of the registered design’s article, as well as any novel creative elements not found in publicly known designs, in order to identify the part of the design that is most likely to attract the attention of consumers (the essential part of the design). Then, focusing on this part, the commonalities and differences identified by observing and comparing the overall composition of both designs should be comprehensively considered to determine whether the two designs share a common aesthetic impression as a whole.

• Essential part of the plaintiff’s design

The plaintiff’s design is a dispenser container for liquid soap that can be used while attached to a wall using a magnet on the back. Therefore, when the container is not attached to a wall, consumers are likely to be drawn to the shape of the front and sides of the container due to its ease of use as a dispenser and its harmony with the interior. However, when the container is used by being attached to a wall, consumers are likely to pay attention to the shape of the back of the container due to concerns about the strength of attachment to the wall.

Furthermore, at the time of the plaintiff’s design application, configurations for liquid soap dispensers featuring a rounded-corner square cylindrical container body, a rounded-corner square lid, and magnets attached to almost the entire back surface of the body were all publicly known. Considering the court’s analysis as stated above at (1), the publicly known or functional features described cannot be said to be the essential part of the plaintiff’s design.

Given that the plaintiff’s design is meant to be attached to the wall of a bathroom or the like, consumers will be most attracted to not only the front of the container body but also the specific shape of the back of the container body including the magnet (wall mounting surface). In this regard, since the configuration of the front of the container body is publicly known, it is appropriate to recognize that the essential part of the plaintiff’s design is the specific configuration of the back of the container body including the magnet (wall mounting surface).

• Determining similarity

The plaintiff’s design and the defendant’s design differ in the specific configuration of the shape of the wall mounting surface of the container body, and this difference concerns the essential part of the plaintiff’s design. Specifically, in the plaintiff’s design, a rectangular sheet-shaped magnet (width-to-height ratio of approximately 1:2.9) is arranged across almost the entire surface, giving consumers a simple and neat impression. In contrast, the defendant’s design features not only a rectangular sheet-shaped magnet (width-to-height ratio of approximately 1:3.3), but also anti-slip sheets arranged in a serif “I” shape above and below the magnet, resulting in a complex structure that does not give a neat impression. Therefore, despite the commonalities between the plaintiff’s design and the defendant’s design, there are significant differences in the essential part, and the overall aesthetic impression received by consumers should be considered different. Therefore, the designs cannot be recognized as similar.

Based on the above, the district court dismissed the plaintiff’s claims. The plaintiff filed an appeal, but the Osaka High Court fully upheld the district court’s decision and denied any infringement of the design right.

Comment

In this case, in order to determine the essential part of the plaintiff’s design, the courts considered the manner of use and function of the article of the plaintiff’s design, emphasized the attention it would attract at the time of purchase assuming use, and took into account publicly known designs. This is because a design for an article is created by a designer who considers usage of the article as well as appearance of the article. This is in line with the standard evaluation in Japanese design practice. It is also important to note that a part related to the function of a design (excluding a shape that is indispensable) tends to be an essential part, as in this case. Regarding the determination of the essential part of a design, the method considering the nature, intended purpose and manner of use of the article, as well as publicly known designs, has been standardized by the Design Examination Guidelines and court precedents. However, since the specific evaluation and results differ for each individual design, court precedents like this one are useful as references. One further point: after the plaintiff’s registered design was published the defendant also obtained two registered designs on which the defendant’s product is based. Therefore, this case could be a meaningful case for intellectual property attorneys.

[1] Although the plaintiff not only argued the similarity of the two designs but also the use of the plaintiff’s design (Article 26 of the Design Act), the judgment regarding use is omitted in this article.