"When we get them back to school, there will be a barbecue."
Students have been encouraged to dress up.
The fee for wearing mufti will provide much of the fundraising.
Mr Shepherd said Jacob's classmates were "very shocked" about Jacob.
"One of their own, suddenly diagnosed as very unwell.
"He's a young, popular, sporting student."
He said the response for the event was "fantastic".
"We were going to be looking at raising money for charity. We had already planned the event, and this is much more fitting," Mr Shepherd said.
"It's far better going to one of our own."
He said there were more fundraisers being planned.