She had taken up the role as principal at the Matauri Bay school in 2007 and had initially been "successful and innovative", increasing the school's roll and improving exam results. However, in 2013 concerns emerged over favouritism towards some students and "having an overly intrusive interest in their private lives".
The students were aged 15 at the time.
Ms Mutu had known them since they were around 9 or 10, and because they commuted some distance to school they had stayed overnight at her home when they were aged 12, 13, and 14.
Ms Mutu lived alone.
She was investigated over Facebook messages between two of the students, one of whom she frequently used a term of endearment for, which was redacted from the decision, although she was also said to use it more widely.
The messages were described in the decision as "the type of conversation a principal should never have been having with a teenage student".
Ms Mutu admitted she had engaged in the conversations, and said "when she looked back she knew she had stepped over the line, but she had never done this before and it was a 'call for help ... even when typing I knew it was wrong"'.
She indicated she did not wish to remain in the teaching profession.
The Teachers Council formally censured Ms Mutu for serious misconduct and cancelled her registration as a teacher. It also ordered her to pay $2000 towards the school to contribute to its legal costs.
