2016 Joo took part in a lot of tournaments: He won silver at the World Championships with the team and at the Asian Games, in the singles he took gold in the Korea Open and qualified self for the Grand Finals. 2007 he reached in the singles and mixed category the quarterfinals at the WTTC and become best defender in the world, again. This position he get to 2017. 2008 he took silver with the team again, at the WTTC. In May this year he came under the top 10 in the world ranings, but doesn't took part in the Olympics. Either at the WTTC and the Grand Finals he reached 2009 the Quarterfinal, 2010 follow bronze (Singles) and silver (Team) at the Asian Games either a bronze medal at the WTTTC. At the Grand Finals either the World Championships he reached the Round of 16, where he lost. At the World Cup he could won bronze in the singles. At the beginning of 2012 he reaclame place number 5 in the world rankings- his best position at all.