The court heard he had been painting throughout the previous night and was supposed to be resting when his son needed a ride to work.
Sefo's wife, who was in court in support of her husband, was supposed to play chauffeur but was delayed coming home from her job and so the task fell to the defendant.
After dropping the teenager off, Sefo was driving home but the late night, combined with alcohol in his system, saw him fall asleep at the wheel.
When he woke up, the car in front had stopped to let Wu and Chen cross the road.
To avoid hitting the vehicle, he swerved but rammed straight into the Chinese couple.
Judge Nicola Mathers said the fact Sefo had no licence was a significantly aggravating factor, as was the fact he had alcohol in his system.
Though his breath alcohol level of 286 micrograms of alcohol per litre of breath exceeded the new limit, it takes a reading of at least 400 for the charge to be elevated to drink driving causing death.
Sefo's lawyer described him as a "hard-working family man" who had been attending church almost every day since the incident.
He had also stopped drinking, he said.
"I accept your sincere remorse for what you've done, which will live with you always," the judge said.
But she had a stern message for road users.
"People are utterly irresponsible on today's crowded roads when they know, or ought to know, they're about to fall asleep," Judge Mathers said.
"The consequences are well known and tragically demonstrated by this case."
Sefo was also banned from driving for a year and will spend nearly three years paying off the reparation in weekly instalments of $30.
