South Korea's KOSPI Index experienced a significant decline at the market opening on Friday, June 5, falling 372.6 points, or 4.31%, to 8,266.81. Major stocks such as Samsung and SK Hynix saw substantial losses, with Samsung dropping 5% and SK Hynix down 7%. Meanwhile, Japan's Nikkei 225 Index also opened lower, decreasing by 486.82 points, or 0.72%, to 66,983.87.