[4] At the 2002 Asian Games in Busan, Iijima paired up with Shinichi Fukushima to grab a silver medal in the men's madison on 11 points, trailing behind the South Korean duo Suh Seok-Kyu and 2000 Olympian Cho Ho-Sung by an ample, twenty-seven point margin after ten intermediate sprint laps.

[5] In the same year, he outsprinted his brother Noriyuki Iijima and Hong Kong's Wong Kam Po to take the men's points race title at the Asian Championships in Bangkok, Thailand.

[6] Iijima turned professional as a road rider in 2005, and eventually stayed with Sumita Ravanello Pearl Izumi for one cycling season, before he left himself without a contract.

As a two-year free agent, Iijima redrafted his efforts to edge out Iran's Hossein Askari and Hong Kong's Cheung King Wai for his second career gold in the men's point race at the 2006 Asian Cycling Championships in Kuala Lumpur, Malaysia, adding a bronze in the men's time trial to his career resume.

Iijima picked up a total of 23 points, and lapped the field once to score a career-high eighth place in a 25-kilometre (16-mile) sprint race.