Justice Simon Moore remanded both men in custody until their next appearance in October.
Detective Senior Sergeant Malcolm Hassall earlier said a team of investigators had been working tirelessly to investigate the circumstances around Tupou's death, and give his family some answers.
"We feel for his family who have been going through an extremely difficult time since his passing, and while we acknowledge this result will not bring him back, we hope it may be able to bring some form of comfort to his family and friends," Hassall said.
Tupou and his family were living in Māngere and had been living in the United States before returning to New Zealand not long before his death.
In a police statement, Tupou was described as "a fun-loving, hard-working young man who regularly attended church and enjoyed social occasions with his friends and family".