In a move reminiscent of the United States’ attack on China-owned Tiktok, the Japanese government is attacking the South Korean owners of LINE. Pressure on the instant messaging app, which is ubiquitous in Japan, threatens to boil over into a diplomatic row, despite the continuing and increasingly obsequious efforts of South Korea’s Yoon Suk-yeol 윤석열 to improve the cross-channel relationship.

LINE was developed by Naver 네이버 as a rival product to Kakao Talk 카카오톡, which took South Korea by storm in 2010. It proved unable to unseat Kakao Talk as South Korea’s “everything app” for instant messaging, payments, and taxi-calling, but succeeded in occupying that position in Japan, which accounted for 83m of the app’s 164m monthly active users worldwide as of 2019. 

Currently, LINE is a joint venture between Naver and SoftBank Group, an investment firm founded by Korean-Japanese investor Masayoshi Son, who acquired a 50% stake in the company in 2021. The joint venture entity,  A Holdings, holds a 65.4% stake in the Line Yahoo Corporation, the operating company for LINE and Yahoo! Japan, which Softbank operated prior to its acquisition of LINE.

The Japanese government, however, has taken issue with an influential messaging app being half-owned by a South Korean company. After a hack and data breach in November 2023 leaked personal information for more than 500k LINE users, Japan’s Ministry of Internal Affairs and Communications demanded that LINE push out Naver, which the ministry blamed for the breach. On April 25, the Digital Society Advancement Committee of Japan’s ruling Liberal Democratic Party summoned an executive from Line Yahoo Corporation to demand a stronger response to the breach.

The attack on LINE is becoming an embarrassment for the Yoon administration, which has justified its capitulation to Japan’s demands on slave laborers and radioactive wastewater from the failed Fukushima Daiichi Nuclear Power Plant with claims that if South Korea “fills the cup halfway, Japan will reciprocate.” The conservative Chosun Ilbo 조선일보 has run a series of blistering articles and editorials accusing Tokyo of treating South Korea “like an enemy country.” In an April 26 press conference, the Rebuilding Korea Party 조국혁신당 said: “The Yoon administration claims improvements in cross-strait relations as its top achievement, but cannot say a word when Japan seeks to take over LINE.”