Northland spokesman Steve Detlaff said that with the parole system, Mason could be out after serving only one third of his sentence.
Judge John McDonald said Mason had sexual intercourse with the girl over two-and-a-half months in public places around Whangarei.
The girl read her victim-impact statement in court and said Mason "just used her". She hoped she could get a protection order so she would no longer see or care about him.
"I hope he never does this to anyone ever again," she said.
Crown prosecutor Catherine Anderson said home detention would not be appropriate considering the extensive harm caused by Mason that would have a far-reaching impact on the girl. The disparity in age, premeditation, an element of grooming, and the fact Mason told the girl to keep quiet about their relationship were the aggravating features of the offending, she submitted.
Mason's lawyer, Kelly Ellis, advocated for a non-custodial sentence based on an early guilty plea, the fact he had a full-time job and the glowing references submitted to court. Media publicity would greatly impact Mason in a small place such as Whangarei, she said.
Judge McDonald said being a wise man with a daughter, Mason was old enough to be the victim's father.
He said most of Mason's messages to her on Facebook and texts were designed to wear her down to a point where she would agree to have sex.
When spoken to by police in August last year, Mason described himself as a mentor who provided support to the victim.
"That was an outright lie. You took advantage of her so she could become your sexual plaything and met her only for sex," Judge McDonald said.
