He also volunteered at Wesley Intermediate School - where he used to attend - mowing the lawns and tending the gardens through the work he did with Te Whangai Trust, a charitable trust providing work and life skills training.
The Sikei family planned to start a trust in his name "to keep his name alive around the community" and to make sure the young people he worked with were still supported.
"He was actually going to sign up to be a cop, that's how much he liked to help his community," said Semisi Sikei.
"But he didn't get the chance…"
Sikei was also a promising rugby player and played for the Eden Rugby Club.
The club paid tribute to the slain 21-year-old on Facebook.
"Rima represented Eden Rugby at U20's and Premier Development levels and had a bright future ahead of him," the post said.
When Sikei's body was released by police his family brought him home, where he lay surrounded by his loved ones - including his parents, four sisters and extended family - for seven days.
His final funeral service was held at the Wesley Community Centre, where he was a regular volunteer, on December 19.
Hundreds of people attended the service, which began with Sikei's casket being carried along Sandringham Rd behind a brass band.
Mourners wore T-shirts emblazoned with images of his face and the date of his death.
Sikei is survived by his parents Maryanne Marama and Selemaea, brother Semisi and sisters Venetia Rose Fauese, Toa Leka, Nancy Maria Sikei and Lesieli Mele Sikei.
"Rima will be forever missed as he was loved by so many people not jus tby his family and friends but the community of Wesley," his brother said.
Sikei's death was one of four alleged murders in Auckland in the same week.
British tourist Grace Millane was allegedly murdered by a man who dumped her body in the Waitakere Ranges on December 1 or 2 - the weekend of her 22nd birthday.
The man charged with her murder cannot be named due to a suppression order.
On December 10 a 34-year-old woman was fatally wounded at her Flat Bush home. It is understood her young son was in the house when she was violently attacked.
Soon after, a 33-year-old farmer contacted police claiming he was responsible.
He was located, arrested and charged with murder.
Both the name of the victim and alleged murderer have also been suppressed.
On December 11 the body of Shannon Shelby Baker, 55, was found deceased at an address on Calgary St, Sandringham.
The death was initially treated as unexplained but was upgraded to homicide after the post mortem.