> This EU born coworker was confused what changed in that 5 year period.

Could be this guy: https://en.wikipedia.org/wiki/Bae_Yong-joon

Or more seriously, a series of Korean dramas that somehow gained immense popularity in Japan. Bae, nicknamed Yon-sama, became so popular that Japanese prime minister (Junichiro Koizumi) joked that he wanted to be like Yon-sama.