"They were 13 and 14 at the time their lives ended in this totally avoidale way," said Crown prosecutor Greg Hollister-Jones.
A two-year-old - restrained only by a lap belt - also in the car, was taken to hospital with injuries but despite extensive damage to the vehicle he was driving, Reihana walked away relatively unscathed.
Mr Hollister-Jones said Reihana, Davey and Morehu had been drinking at a Welcome Bay home before deciding to go to their family urupa on Christmas Day, 2011.
Only Morehu had a licence and that was a restricted class. There was talk of racing to the cemetery to see who would get there first, Mr Hollister-Jones said.
Reihana drove Morehu's car and after performing a dangerous overtaking manouever lost control of the vehicle colliding with 39-year-old Brett Mc Cready who was westbound on Welcome Bay Road.
The collision caused Mr McCready's ute to flip although he was not injured.
Mr Hollister-Jones said Reihana would later blow nearly twice the legal breath alcohol limit and the deaths were "absolutely predictable".
"The accused, Mr Reihana was drunk and the other two accused had also been drinking," he said.
"This was alcohol-fuelled madness, all were unlicensed and were deliberately racing each other at high and reckless speeds in unsafe vehicles on a winding road."
The trial before Justice Murray Gilbert is set down for three weeks with 36 witnesses to give evidence.
