The boy's lawyer, Maria Pecotic, argued today that if the boy was named, he would be publicly stigmatised.
She said it would not help him with any future rehabilitation, and he "would always have that over his head".
"Past that time, what happens to him when he is released into the community and tries to continue on and start his life?
"In this situation we have a child who has yet to develop and grow... if you publish his name we are labelling him, stigmatising him."
At trial in the High Court at Auckland, the court heard how the defendant was no normal teenager and had suffered a "serious traumatic brain injury" when he was struck by a vehicle at age 8.
His mother drank alcohol heavily and took drugs during her pregnancy, Justice Lang said, and the boy had symptoms of Foetal Alcohol Syndrome.
He was addicted to synthetic cannabis at the time of the attack on Mr Kumar, and was living in a house that was used by drug-takers.
Today, Ms Pecotic said the boy "had the worst possible start in life".
"This is a young man that shows incredible promise despite the incredibly difficult start he's had.
"Huge change has happened for him since he has had the rehabilitation that's been put into him, since he's been in care."
She said it was not in the public's interest to publish the young boy's name.
"He's a first offender, he should not be regarded as beyond help - even though the offence itself was serious, he has his whole life ahead of him and his whole future."
At the trial, Justice Lang ordered no images of the boy be published, and his image was suppressed.
Ms Pecotic argued that this should also extend to the boy's name, because image and name were "part and parcel" of a person's identity.
"It's an all or nothing."
However, Crown counsel Annabel Markham said it was in the public's interest for the young boy to be named.
She told the court the public confidence of the criminal justice system could be undermined if name suppression remained in place, despite the boy's young age.
Bell Gully lawyer Tania Goatley also made submissions on behalf of several media organisations, including New Zealand Herald publisher NZME, at today's hearing.
She argued the boy's name suppression should be lifted.
Ms Goatley said the trial had been reported extensively, and argued the boy only narrowly escaped the most serious crime in the crimes act.
The reserved decision of Justices Harrison, Wild and Miller will be released in writing at a later date.
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