Kahi Loses KAHI Trademark Fight After 25 Drama PPLs and 10 Million Sales

A cosmetics brand that sold 10 million units in about 18 months just beat After School's Kahi in court over her own stage name. The ruling voided her KAHI trademark for dietary supplements, and it became final on May 20.

The Patent Court ruled on April 23 in favor of the cosmetics company, Kahi (the brand). Kahi the singer appealed, then withdrew the appeal a week later. That left the loss standing. The court made the decision public as a notable ruling on the 2nd of this month, and the news surfaced on the 21st.

How a stage name became a trademark fight

Kahi filed for the KAHI mark in May 2021 for use on dietary supplements and similar goods. Registration was approved in December 2023. The cosmetics company then challenged it, arguing the identical English name would confuse shoppers about who makes what.

Her side had a straightforward defense. She had performed as Kahi before the cosmetics brand existed and said she was simply using her own name. The Intellectual Property Trial and Appeal Board initially agreed with her, finding that cosmetics and supplements are different products without a close economic link.

The Patent Court saw it differently.

What swayed the Patent Court

The judges pointed to the brand's reach. It has sold products since April 2020, and its products appeared as paid product placement (PPL) in 25 dramas, including Extraordinary Attorney Woo. It passed 10 million units sold roughly a year and a half after launch. By the time Kahi's trademark was approved in December 2023, the court concluded, the cosmetics brand was already widely known to consumers.

The product-difference argument failed too. The court said cosmetics and beauty-oriented supplements share a purpose, health and beauty upkeep. It also noted that cosmetics makers such as Amorepacific and LG Household & Health Care increasingly sell health foods as well.

The panel's conclusion: given the growing trend of one company making both, consumers could reasonably mistake the two products as coming from the same company.

One more detail stings. Kahi reportedly registered the mark but never actually used it on a product.

Who Kahi is

Kahi debuted in 2009 as the leader of After School, known for hits like "Diva," "Because of You" and "Bang!" She later moved into solo work and musical theater. She married a businessman in 2016 and has two sons.