"She describes herself as feeling as an outsider and distances herself from people in her life.''
Chadwick took the girl to a property with the intention of raping her, the court heard.
"You there used fly spray despite her resistance, in the end you forced her to inhale a significant quantity which had the effect of stupefying her,'' Justice Priestley said.
"You then ... pushed her onto a couch. Her ability to resist you was minimal.''
Justice Priestley said after Chadwick raped the girl he got dressed and took her back home.
She never wanted to return to Rotorua other than to visit the grave of a close family member.
Chadwick was told he would serve a minimum of five years of his 10-year sentence.