COURTESY BY: https://images.dawn.com/ A video ad from Nike Japan against bullying and racism that features biracial athletes and other minorities, such as those of Korean descent, has prompted a sharp online response including calls to boycott the company. Japan has traditionally prided itself on being racially homogeneous, although successful mixed-race athletes such as tennis star Naomi Osaka are challenging that image. The commercial, “Keep Moving: Yourself, the Future,” released on Nov 30, shows several teen girls bullied in school over their race or other differences, but who ultimately find confidence…