"I pray every second of every moment that he will come home to us," she said.
Mitchell said her brother worked full time as a strawberry picker in Whakamarama and his disappearance was "totally out of character".
She was not sure what Julian was wearing when he disappeared, but he was known to wear Hunting & Fishing tops and shorts regularly, she said.
Inside Julian's flat, there were no clothes or belongings missing, and nothing to suggest that he was feeling troubled about anything, a distraught Mitchell said.
Mitchell said she had not been able to eat or sleep since he went missing, and she and her family were "barely keeping it together".
"We need Julian home and not knowing why or how he disappeared or anything about his possible whereabouts is just destroying us."
Mitchell said police with tracker dogs searched an area in the Ōropi Rd and Pyes Pa area last week.
"I spoke to the police again this morning and they have told me they have no leads but they will keep on searching as new information comes to hand.
"Someone out there must know something and I beg you please, speak up," she said.
"I love my big brother more than anyone in the world. He deserves to come home and his two beautiful poor babies need him home."
Mitchell said her brother was the "most caring, amazing man" and she did not understand why he had suddenly disappeared.
"We desperately need answers."
A police spokesperson confirmed police were continuing to making inquiries.
"If anyone has any sightings and information that may assist police, they should phone 105 quoting file number 200128/0613."