[3] Suenaga is an economics graduate at Hosei University in Tokyo.

Suenaga competed in a breaststroke double at the 2008 Summer Olympics in Beijing.

[4][5][6] In the 100 m breaststroke, Suenaga posted a thirteenth fastest time of 1:00.67 on the first day of preliminaries to secure his spot for the semifinals.

[7][8] Followed by the next morning's session, Suenaga failed to qualify for the final, as he finished his semifinal run by matching his time and placement from the heats.

[9] Four days later, 200 m breaststroke, Suenaga missed the semifinals by 0.11 of a second, as he shared his seventeenth-place tie with Norway's Alexander Dale Oen in 2:11.30.