Tsukahara represented Japan at the 2008 Summer Olympics in Beijing where he competed at the 100 metre sprint and placed second in his first heat after Churandy Martina in a time of 10.39 seconds. He qualified for the second round in which he improved his time to 10.23 seconds, finishing third behind Martina and Michael Frater. In the 100 m semi-finals Tsukahara achieved a time of 10.16 seconds, his best of the season, but finished in seventh place, failing to qualify for the final.[2]
Together with Shingo Suetsugu, Shinji Takahira and Nobuharu Asahara, Tsukahara also competed in the 4x100 metres relay final at the 2008 Summer Olympics. In their qualification heat, the team placed second behind Trinidad and Tobago, ahead of the teams from the Netherlands and Brazil. Their time of 38.52 s was the third fastest out of sixteen participating nations in the first round and they qualified for the final. There they sprinted to a time of 38.15 seconds, placing third after the Jamaican and Trinidad teams, winning the bronze medal.[2] However, in January 2017, Jamaica's gold medal was revoked after one of their athletes was found to have been doping, meaning that the Japanese team received silver. The achievement was a historic one in terms of Japanese olympians; it is the first track medal won by Japanese athletes in 80 years, as well as being the first medal won by male Japanese athletes.[3]
Tsukahara had a strong start to the 2009 season, improving his 200 m best in early May to 20.61 s. He also set a new 100 m personal best at the 2009 Osaka Grand Prix. He easily won with a time of 10.13 seconds but still felt that he was capable of running faster.[4]