A bus driver and tour guide has been jailed for sexual violation after a drunk and drugged incident with a Japanese tourist.

The 40-year-old man, Christopher Joel Bruce, who is also described as a teacher, was found guilty of sexual violation by unlawful sexual connection at the end of a Christchurch District Court jury trial last month.

He had earlier pleaded guilty to a charge of supplying the woman with cannabis.

His wife has now gone to Japan, taking with her their two children, and the man has lost any prospect of further employment in his chosen fields. He speaks Japanese.

Defence counsel Trudi Aickin said Bruce had now written a letter of apology to the victim and had been saddened to read her victim impact statement.

She said it had been a brief incident, without any associated violence or degradation, and without premeditation.

The jury may have found him guilty on the basis that he did not have reasonable grounds for his belief that the woman was consenting.

She said Bruce's family continued to support him and $5000 had been raised to offer the complainant as reparations for emotional harm.

Crown prosecutor Deirdre Elsmore said the offending was more serious than a brief incident. It had gone on for several hours.

The woman had met him as a bus driver and tour guide, and had trusted and relied on him to behave properly when she went to his home as a guest at a barbecue.

Bruce had continued with his advances when she kicked him away and told him "No" in Japanese.

"This really was a case of ignoring all the signs from her that his advances were unwelcome," said Elsmore.

Judge Callaghan said the woman had been grossly affected by alcohol and by her first use of cannabis, which Bruce had given her. There was some evidence of familiarity between the two earlier in the evening.

It was unclear how the woman came to be in the bedroom. She may have wanted to lie down because she was tired.

She lay down, with her clothes on, but woke to find Bruce on top of her and both of them naked. She kicked him away and told him to stop several times, in Japanese.

"She denied having any sexual interest in you," said the judge.

Several incidents of sexual violation then occured as she drifted in and out of consciousness.

"She wasn't in a position to consent," said the judge.

The jury's verdict must be seen as rejecting any suggestion that she was consenting to any sexual behaviour of this nature. It showed he was preying upon her in her state of intoxication.

Bruce was intoxicated himself but that was no defence.

Judge Callaghan noted that Bruce was a first-time offender, and he was showing remorse with his offer of reparations.

He reduced his sentence for his good record, his remorse and the offer he had made, and jailed him for two-and-a-half years. He ordered the payment of the $5000 emotional harm reparations.

NOTE: In 2015, Christopher Joel Bruce's charge of sexual violation by unlawful sexual connection was quashed on appeal and he was discharged without conviction on the charge of supplying cannabis.