His classmates were disbelieving when they heard about the plan.
Reaction to the new look was mixed, with David noting "it's like carpet -- I'm going to get rug burn for the rest of my life".
Luckily Christian's mother, Jane Neumann, was on hand with bandannas and beanies.
Society manager Jeanine Gribbin said she was blown away by the boys' decision.
"I just thought 'wow' what a great thing to do. He [Christian] decided that he wanted to do it," she said.
"And it's a really interesting thing. It's a great thing for kids to do."
The boys also plan to take part in the Relay for Life fundraiser next March.
Money raised would go towards the centre's support services, which include driving patients to Wellington and Palmerston North for treatment, Ms Gribbin said.
All donations to the society are used in the region from where the funds came.
The organisation receives no government funding.