In Kwangdong Pharmaceutical Co., Ltd. (Kwangdong) v. Tortoise Pharmaceutical Co., Ltd. (Tortoise), Kwangdong filed an application on January 11, 1983 to register the trademark TORTOISE and the Korean word KEOBUKPYO (meaning "Tortoise brand") for pharmaceutical products in Korean Class 10. Kwangdong used the trademark on pharmaceutical products for approximately 10 years prior to its registration date of March 24, 1984. On January 23, 1989, Tortoise registered the trade name "Tortoise Pharm" with the Commercial Register and commenced business under this name on February 13, 1989.

Kwangdong filed "a confirmation-of-scope" suit with the Trial Board (TB) of the Korean Industrial Property Office (KIPO) seeking a declaratory decision that the trade name "Tortoise Pharm" fell within the scope of use protected by its registered trademark TORTOISE. Kwangdong argued that "Tortoise" was the main portion of the trade name "Tortoise Pharm" and was similar to its registered trademark which was well-known in the local pharmaceutical industry prior to the registration of the trade name, thereby resulting in the likelihood of confusion among consumers as to the source of the respective goods. The TB held that Tortoise's use of the trade name fell within the scope of use protected by Kwangdong's registered trademark.

Tortoise appealed this decision to the Appellate Trial Board (ATB) of the KIPO and argued that, since Kwangdong's trademark TORTOISE was used on pharmaceutical products and the trade name "Tortoise Pharm" was used in connection with services involving the sales of pharmaceutical products at the wholesale level, the use of the trade name and the trademark would not cause confusion. The ATB confirmed the decision of the TB ruling that the trade name Tortoise Pharm was used in a manner consistent with that of a trademark. The ATB held that, since the registered trademark TORTOISE was well-known in the pharmaceutical industry prior to the registration of the trade name "Tortoise Pharm", its use on pharmaceutical products was deemed to be an attempt to profit from the well-known trademark, and the use of the trade name on identical or similar goods may cause confusion as to the origin of the goods and constitute unfair competition.

Tortoise appealed this decision to the Supreme Court and the appeal was dismissed on the grounds that, although "Tortoise Pharm" was used as a trade name, since such use distinguished its services from others, the trade name was used as a service mark as well as a trade name. In the circumstances, the Supreme Court held that the rights in the trademark TORTOISE barred the use of the trade name "Tortoise Pharm".

Although ordinarily a trademark registration cannot prevent the use of a trade name in Korea, this decision stands for the proposition that, where the trade name is being used with the intention of competing unfairly and the trade name is also used as a service mark, its use may be barred.