"So we used to go Wanganui quite a lot, and we both loved it. Great climate, nice people, good sense of community - it really has been the perfect move for us."
A roll of 100 at St Marcellin means the classes are small, with between 15 and 20 students per class, he said.
"We really have a good family atmosphere here."
Mr Harrison has taught in both state and Catholic schools, but his preference is definitely Catholic schools, he said.
"I like the Catholic system and the holistic development we have for our children."
His aim is to find better ways of organising student achievement at St Marcellin, he said.
"To look at new programmes and ways to achieve. I want our students to do really well."
Even though some St Marcellin students have left the small Catholic school in Tawhero to go on to the bigger intermediate schools of Rutherford Junior High and Wanganui Intermediate School, this year most of the senior students have stayed on at St Marcellin, he said.
And the golden rule of St Marcellin School reigns, he said.
If you want to teach young people,
You must love them all equally.
"And we do."