He attended rugby nurseries Tokai Dai Gyosei High School with Koji Uehara and Yoshinori Tateyama, where the three were classmates, and Kyoto Sangyo University.

[4] On 14 May 2006, Ohata scored three tries for Japan against Georgia at Hanazono Stadium, in doing so claiming the world record for tries in rugby test matches.

However, unlike Campese and Habana, only a quarter of Ohata's tries were scored against major rugby union playing nations, causing controversy in some media.

[7] Ohata did not take part in the Rugby World Cup 2007, as he had ruptured his left Achilles tendon in an August practice match against Portugal.

He had only just returned that month to the national side, having recovered from a right Achilles tendon rupture in January.