He is the current International Racquetball Federation (IRF) World Champion in Men's Doubles, winning the title with Samuel Murray in 2024.

[16] Iwaasa played in the Racquetball Canada National Team Selection Event in February 2012 in Regina, where he lost in the Round of 16 to Francis Guillemette, 16–14, 15–8.

[18] Iwaasa played Men's Doubles with Kurtis Cullen that year, and they lost in the quarterfinals to Mike Green and Kris Odegard, 15–2, 15–3.

[19] Iwaasa played in the 1st Racquetball Canada National Team Selection Event of the 2012–13 season in November 2012 in Kelowna, British Columbia, where he lost in the quarterfinals to Tim Landeryou, 7–15, 16–14, 11–4.

[20] In the 2nd Racquetball Canada National Team Selection Event that season in February 2013 in Brossard, Québec, where he defeated Samuel Murray in the quarterfinals, 15–13, 16–14, but lost to Mike Green in the semi-finals, 15–13, 15–2.

[21] Iwaasa played Men's Doubles with veteran Mike Green at the 2013 Canadian Championships in Langley, British Columbia, and they won the title, defeating Lee Connell and Francis Guillemette in the final, 15–5, 15–6.

[23] In November 2013, Iwaasa finished 3rd at the 1st National Team Selection Event of the 2013–14 season in Winnipeg, where he reached the semi-finals by defeating Nathaniel Husulak in the quarterfinals, 15–6, 15–7, but lost to Mike Green, 15–6, 15–9.

[24] In the 2nd National Team Selection Event that season, he again played Green in the semis, and lost but in three games, 15–12, 8–15, 11–1, in Brossard, Québec in January 2014.

[26] Iwaasa was 3rd in Men's Singles for the second time, as he lost to eventual champion Vincent Gagnon, 15–10, 15–17, 11–6, in the semi-finals, but won the 3rd place match versus Samuel Murray, 13–15, 15–6, 11–8.

[27] That summer Iwaasa played for Canada for the first time by participating in the 2014 Pan American Sports Festival in Guadalajara, Mexico, where he defeated team-mate Samuel Murray, 15–9, 10–15, 11–3, in the Round of 16,[16] but lost to David Horn of the US in the quarterfinals, 8–15, 15–14, 11–6.

[16] In November 2014, Iwaasa defeated Samuel Murray, in the quarterfinals, 15–9, 15–10, of the 1st National Team Selection Event of the 2014–15 season in Kitchener, Ontario.

In the medal round, he defeated Fernando Rios of Ecuador and Jake Bredenbeck, 15-4 15–9, before losing to Mexican Álvaro Beltrán in the quarterfinals, 15–3, 15–7.

[35] Following the Pan American Games, Iwaasa, as a member of the Church of Jesus Christ of Latter-day Saints, went on a two-year mission to Japan.

[36] Returning to competition, Iwaasa played the 1st National Team Selection event of the 2017–18 season in Vernon, British Columbia, where he lost in the semi-finals to Samuel Murray, 15–11, 15–8.

Iwaasa represented Canada at the Racquetball World Championships for the first time in 2018 in San José, Costa Rica, where he played Men's Singles.

Iwaasa was a member of Team Canada for the 2019 Pan American Racquetball Championships in Barranquilla, Colombia, where he reached an international final for the first time.

They beat Costa Ricans Andres Acuña and Felipe Camacho in the semi-finals, 8–15, 15–1, 11–3, but lost to Bolivians Roland Keller and Conrrado Moscoso, 2–15, 15–9, 11–2, in the final.

Iwaasa also played Men's Singles in Barranquilla, where he lost in the Round of 16 to eventual Pan Am Champion Carlos Keller of Bolivia, 15–10, 15–9.

Iwaasa was runner up in Men's Singles at the 2019 Canadian Championships, as he lost in the final to Samuel Murray, 15–3, 15–6, in Langley, British Columbia.

Iwaasa won Men's Doubles with Samuel Murray at the 2022 Pan American Racquetball Championships in Santa Cruz de la Sierra, Bolivia.

[54] He also played Mixed Doubles in Bolivia with Juliette Parent, and they lost in the quarterfinals to eventual gold medalists Mexicans Rodrigo Montoya and Samantha Salas, 15–6, 15–9, 15–12.

In Men's Doubles, he and Samuel Murray defeated the Independent Athletes team of Edwin Galicia and Juan José Salvatierra, 11-9, 8-11, 11-7, 8-11, 11-7,[63] in the semi-finals, and then in the final lost to Mexicans Javier Mar and Rodrigo Montoya, 6-11, 11-7, 12-10, 12-10.

[67] Iwaasa also got a bronze medal in the Men's Team event, as he helped Canada beat Guatemala in the quarterfinals, but they lost to Mexico in the semi-finals.

[1] They defeated Bolivians Kadim Carrasco and Conrrado Moscoso in the semi-finals, 5-11, 12-10, 11-7, 8-11, 11-8, and then Mexicans Andree Parrilla and Eduardo Portillo in the final, 11-5, 6-11, 11-8, 4-11, 11-6.