Kaua was motivated by those family members, but also his friends and his faith, to go for the role of head boy.
It was a big process to become a leader, with students required to make speeches at a Year 12 retreat, attend leadership camps, fill out application forms and do interviews.
So far Kaua has been involved in many more meetings than he is used to, but the highlight has been helping out others.
"I'm enjoying mixing with our Year 9s, welcoming them to our whānau and it's good because when you go around the school, they know your name and you know theirs.
"It makes them feel like they know us and that they're one of us. I enjoy being there for others and helping them out if they're lost."
Kaua is a keen sportsman and is looking forward to a big term two in which the house groups will get together and participate in activities as part of Cullinane Day.
For his co-leader, Cullinane College head girl Christie Wallace, term two presents several events that have her feeling nervous.
Wallace, also 17, won the Pei Te Hurinui Jones Trophy last year in the Ngā Manu Kōrero secondary school speech competition for the Aotea region in Waitara.
She will be participating in the 2019 Kapa Haka Regionals as well as trying to back up last year's speech performance at the regional competition in Opunake on June 27.
"I've just been worrying about them all the time because I'm the senior Māori speaker so we have the 12-minute prepared speech to do and also an impromptu one," Wallace said.
"It's also in te reo Māori, which is nerve-racking, but it makes my parents pretty proud and I'm proud to represent my culture."
Wallace represents Te Awa Tupua and Te Atihaunui a Pāpārangi on her dad Quentin's side and Ngāti Apa and Ratana on the side of mum Toni.
She was inspired by her parents, who she says are two of the hardest-working people she knows, but it was the words of someone else that made her chase the role of head girl.
"I was inspired by one of the former teachers of the school, Kamaka Manuel," Wallace said.
"I remember way back in Year 9 he said, 'you know, if you study hard and try your best you could stand as head girl', and that's what I am today. I owe a lot of that to him."
Wallace went to Te Kura Kaupapa Māori O Te Atihaunui-A-Paparangi and Te Kura o Ratana before Cullinane.
She began seeing her potential during leadership camps and said it was a thrilling experience when principal Justin Harper told her she was head girl.
"Getting ready to transition into Year 13 I never would have thought I'd see myself as the head girl, especially with those who have made it in the past at Cullinane.
"I feel very privileged to be in this position. I've always wanted to be that role model that people can look up to."
The two head students are backed up by deputy head boy Lucas Reardon and deputy head girl Ally Keenan.