Starbucks Korea announced a complete one-day shutdown of over 2,000 stores on 22 June 2026, requiring all staff to attend mandatory training on modern Korean history and social sensitivity. The unprecedented move follows a public backlash over a 'Tank Day' promotion for a tumbler series launched on 18 May, the anniversary of the 1980 Gwangju Uprising, when military forces killed hundreds of pro-democracy protesters. The promotion, which included the slogan 'thwack on the desk'—a phrase tied to the 1987 torture death of student activist Park Jong-chul—was approved after AI-generated suggestions were used, and key managers failed to review campaign materials.

The controversy triggered widespread boycotts, public destruction of Starbucks merchandise, and severed ties with government ministries. CEO Seo Jung-jin was dismissed the same day the campaign was pulled. Starbucks Korea’s parent company, Shinsegae Group, confirmed that Chairman Chung Yong-jin would also undergo the same training. The store closures are expected to cost $1.4 million in lost sales.

Payment data showed a 26% drop in transaction volume immediately after the incident, with only partial recovery in early June. Starbucks’ global headquarters issued a formal apology to the May 18 Foundation, representing Gwangju victims. While no deliberate intent was found in an internal probe, Seoul police have registered Chung and the former CEO as criminal suspects. The incident underscores the high stakes of historical awareness in marketing within socially sensitive contexts.