His older brother, Takashi Iwamura, was also a professional baseball player who spent two seasons in the Kintetsu Buffaloes' farm system.

The posts were due to the commissioner of Major League Baseball on November 10, 2006; the highest bidder would be granted the right to negotiate a contract with Iwamura.

Incidentally, Daisuke Matsuzaka, who signed a six-year, $52 million contract with the Boston Red Sox that same year, is a close friend of Iwamura.

On November 14, information leaked that the highest bidder and consequently the team that won the right to negotiate with Iwamura was the Tampa Bay Devil Rays.

However, he eventually won the starting third base job, despite the competition, and began his major league career at his natural position for the Devil Rays.

However, he was hit in the eye on a freak play while chasing down a fly ball and spent time on the disabled list until May 28.

In September 2023 the Rays, to honor this landmark moment in the team’s history, unveiled a statue outside of Tropicana Field depicting Iwamura after recording the out.

Tampa Bay Rays shortstop Jason Bartlett caught the throw from the catcher, kneeling down in the process.

[8] The next day the two teams played again, and in the second inning, Tampa Bay Rays starting pitcher James Shields threw a pitch to Crisp which hit him below the waist.

[11] Midway through the 2008 season, Iwamura got a mohawk haircut, a style which soon spread to many of his teammates and then Rays' manager Joe Maddon.

As the team went on to become American League Champions, many fans around the area also sported the "Rayhawk", which usually involved a wide and short patch of hair running from front to back atop an otherwise bald or closely shorn head.

After being slid into by Marlins infielder Chris Coghlan, Iwamura fell to the ground and eventually had to be carted off the field.

[19] Iwamura was designated for assignment by the Pirates on June 16, 2010 after hitting only .182 in Pittsburgh and showing limited range at 2nd base.

After failing to work out a suitable trade, Iwamura joined the Pirates' Triple-A affiliate team Indianapolis Indians on June 22, 2010.

He was expected to bat in the cleanup position for his new team; however, he experienced injuries and had a bad slump during his 2 years with the Golden Eagles.