## Facts

- Sony Kabushiki Kaisha owned multiple Japanese trademark registrations for “WALKMAN / ウォークマン,” including registrations covering electronics as well as clothing and footwear, and licensed the mark for diverse goods under strict quality and advertising controls.
- By the early 1980s, “Walkman” had become widely known in Japan and strongly associated with Sony; survey evidence showed most consumers linked “Walkman” to Sony.
- Yugen Kaisha Walkman operated a retail shop specializing in shoes and clothing and used “Walkman / ウォークマン” as its corporate name and as a visible designation on shopping bags, receipts, signage, advertisements, and related materials.
- The retailer sold third-party manufactured goods; the “Walkman” designation identified the shop and appeared on materials accompanying sales of the goods.
- Sony sued seeking (i) an injunction against use of “Walkman” on business materials, (ii) an order requiring a change of the defendant’s trade name, and (iii) damages.

## Issues

1. Whether the retailer’s display of “Walkman / ウォークマン” on shopping bags, receipts, and similar materials constituted “use as a trademark” under the Trademark Act.
2. Whether the defendant’s indicia were similar to Sony’s registered “Walkman” marks such that the defendant’s uses infringed Sony’s trademark rights.
3. Whether using “Walkman” as a trade name and business indication constituted unfair competition by creating a likelihood of confusion—including confusion as to affiliation or licensing—under Unfair Competition Prevention Act art. 2(1)(i).

## Decision

- The court entered judgment for Sony.
- The court held the defendant’s use of “Walkman / ウォークマン” on shopping bags, receipts, and similar items was trademark use because it functioned to distinguish goods sold by the defendant from goods sold by other retailers.
- The court found the defendant’s “Walkman” indicia similar to Sony’s registered marks and concluded the defendant’s uses infringed Sony’s trademark rights.
- The court held the defendant’s trade name and business use of “Walkman” was an unfair competition act because it was likely to cause consumers and traders to mistakenly believe a special relationship (e.g., group-company or licensing relationship) existed between Sony and the defendant.
- The court ordered cessation of the challenged uses, required the defendant to stop using “Yugen Kaisha Walkman” as its trade name (effectively requiring a trade-name change), and awarded damages.

## Legal Principles

- A sign is used “as a trademark” when used in a manner that performs the mark’s function of distinguishing one party’s goods from others; retailer use on packaging and sales materials can qualify when it identifies goods sold under the retailer’s responsibility.
- Word marks that are identical or highly similar in appearance and sound may be found similar for infringement purposes, particularly where the term is distinctive and strongly associated with the rights holder.
- “Acts causing confusion” under Unfair Competition Prevention Act art. 2(1)(i) include not only confusion as to identical source, but also confusion that suggests a special organizational, economic, or transactional relationship (including licensing or group affiliation).
- A competitive relationship between the parties is not required to establish confusion-based unfair competition where a well-known business or product indication is appropriated as a trade name or business identifier.

## Conclusion

The court protected Sony’s well-known “Walkman” designation by treating the retailer’s use on bags and receipts as trademark use, finding infringement based on similarity, and broadly applying unfair competition law to stop trade-name appropriation likely to create mistaken beliefs of affiliation or licensing.


Sony Kabushiki Kaisha v. Yugen Kaisha Walkman, 1598 Hanrei Jiho 142 (Chiba Dist. Ct. 1996)