Tenor Masashi Kishimoto had never seen a rugby match before he watched Australia play Argentina live in Sydney at the opening of the Rugby World Cup in Australia last week.

But the 25-year-old singer from Hyogo Prefecture will get to see a few more rugby games over the next few weeks -- he's touring with the tournament's World Choir and is one of two singing the Japanese national anthem "Kimigayo" before Japan matches.

"I still don't understand the rules, but I'm sure I will by the end of the World Cup," he said in Townsville, Queensland, where he is based with the Japanese team.

Having previously only sung in front of crowds of a few thousand people, being part of the 40-member, 20-nationality choir singing to an 82,000 capacity crowd at Telstra Stadium in Olympic Park on opening night was a momentous occasion for Kishimoto.