The newly-graduated police officer and former Hillcrest High student moved to New Zealand from Korea with his family about 10 years ago and started in the sport a few years earlier on the advice of his father.
"My dad told me to do it, so I did," he says, laughing.
"What I like about judo is it is all about action and reaction," he says.
Sean, a member of the Metro Judo Club, can train three times a day but his work with the Hamilton police often means he only manages one daily session.
He hopes a training camp after the Paris Grand Slam, Austria World Cup and Germany Grand Prix will be a good chance to exclusively concentrate on judo.
Although work consumes a lot of his time, Sean says his police bosses have been supportive, allowing him time off and sponsorship to help with his expenses.
As with a lot of minor sports in New Zealand, judo is mostly self-funded by the individual athletes and Sean says while sponsorship is thin on the ground, he's grateful to John Lawrenson, who owns Bar 101, Furnace, Keystone and various other Hamilton bars, for his financial backing.