The pair were about to do renovations on their home and were looking forward to getting married one day, Mr Horwood earlier told the Herald.
Little did they know that Kale had just spent the day celebrating his birthday, which included a flying lesson and spending time at the beach with family, before they made their way back to Hamilton.
The court heard that when they hit Karapiro, about 6pm, Kale's people mover vehicle slowly veered left, going onto the grass verge for a short time before it then sharply veered back onto State Highway 1, on a 45 degree angle, crossing the centre line and crashing head-on into Mr Horwood's vehicle.
Mr Horwood, who suffered only bumps and scratches, said he tried to swerve to avoid the collision but it was too late.
Kale's wife suffered serious injuries and was airlifted to Waikato Hospital.
When spoken to by police, Kale, a co-director of Kiwi Tourism Limited, said he must have fallen asleep.
He was remanded on bail to reappear for sentencing in July.
In the meantime, he will attend a restorative justice conference with the victim's family.