A player on the Chicago Cubs, if reading this in the future, a former player for the Chicago Cubs. However his baseball career is of little to no relevence to those who use his name as it should be, an expletive. Commonly used as an acceptable replacement for the word "fuck" or any swear. Fukudome, and Kosuke can be used in many ways, such as shortened versions down to "fuku".
Example 1:
Guy 1: "Man, that test was horrible, I studied a lot but I'm not sure if I did well."