ABSTRACT
In Japan, unregistered well-known trademarks are protected under the Unfair Competition Prevention Act. The trademark holder counterclaimed for trademark infringement under the Trademark Act. The defendant asserted counterclaims seeking an injunction against the plaintiff’s use of EEMAX marks under the Trademark Act. The plaintiff alleged that exercise of the defendant’s trademark rights would be barred because both the ’484 trademark and the ’316 trademark were registered in violation of Article 4 of the Trademark Act. The purpose of Article 4 of the Trademark Act is to prevent confusion as to source of the products bearing marks which are well known among consumers as well as to balance the interests of the person who is recognized as the holder of a well-known mark against the interests of an applicant of trademark registration. The Trademark Act provides a defence of prior user of a trademark, which was totally ignored by the Supreme Court in this case.
