From then until February last year, both engaged in inappropriate behaviour, including the student sending the teacher thousands of graphic emails which confessed her love for him, attaching explicit photos and demanding sex.
They also met several times where the student would attempt to touch the teacher, who rebuffed her, the report said.
During that time, the teacher failed to report the situation to the principal and "thus allowed the situation to become increasingly inappropriate in the circumstances where the emotional wellbeing of the student was being adversely affected by the relationship", it said.
The school's deputy principal, who was acting principal at the time, told the tribunal the man was fit to teach.
"She said that while casual reading of some of the information might lead to a different conclusion, [the teacher] was fundamentally a decent person."
The man's girlfriend told the tribunal he had a "sheltered" view of the world and in relationship matters he was unsophisticated, the report said.
"She asserted that 'he loves teaching and is dedicated to his students' learning'."
In the report, tribunal chairman John Hannan said the teacher "exhibited a woeful and very disappointing failure to recognise his transgression of boundaries over a very extended period of time".
The tribunal was concerned he failed to recognise that he was dealing with a very serious situation, where the only solution was to immediately disclose everything to the principal and seek guidance on the best way to handle the situation.
"Her behaviour became extreme. He should have protected her by not allowing himself to get into situations where this behaviour could manifest itself," Mr Hannan said.
The teacher had learned a "hard lesson" and was unlikely to repeat the behaviour, he said.
The tribunal censured him and ordered he take part in a guidance programme that addressed teacher, student boundaries.
He was also to tell prospective employers for the next three years of the decision and was ordered to pay half the costs incurred by the tribunal and the Complaints Assessment Committee, which investigated the case.