Patent Court Upholds Cosmetics Firm KAHI’s Trademark Over Former After School Member Kahi’s Brand

On April 23, the South Korean Patent Court ruled in favor of cosmetics company KAHI in a trademark dispute involving the use of the name “Kahi.” The case centered on the dietary supplement brand “Kahi,” created by former After School member Kahi, who sought to register the trademark for her products.

KAHI, a cosmetics company, had applied to register the “Kahi” trademark in May 2021 and received approval for registration in December 2023. Subsequently, KAHI filed a lawsuit seeking to invalidate Kahi’s trademark registration, arguing that the identical English spelling of the marks could cause consumer confusion regarding the origin of the products.

Kahi’s legal team contended that the stage name “Kahi” had been in use well before KAHI’s establishment, asserting prior rights to the name. Initially, the Patent Trial and Appeal Board sided with Kahi, determining that the products were neither similar nor economically related.

However, the Patent Court reversed this decision, emphasizing that KAHI had already gained significant public recognition by the time Kahi’s trademark was registered in December 2023. The court highlighted that since April 2020, KAHI had promoted its products through placements in 25 television dramas, including the popular series “Extraordinary Attorney Woo.” Moreover, KAHI’s sales had surpassed 10 million units within approximately 18 months of launching.

The court also addressed the argument that cosmetics and dietary supplements were distinct product types. It rejected this claim, noting that both categories serve beauty and health purposes and are applied directly to the body. The court further observed that consumers might reasonably assume the products originated from the same company, especially given the trend of major corporations like Amorepacific and LG Household & Health Care marketing both cosmetics and dietary supplements under unified branding.

Following the ruling, Kahi initially appealed but withdrew her appeal a week later, rendering KAHI’s victory final on May 20.

In a related note, Kahi was reported to have attended a K-pop dance workshop in Los Angeles on June 14.

This case underscores the complexities of trademark rights when personal stage names intersect with established commercial brands, particularly in overlapping sectors such as beauty and health products.