"Storm only need to win by one point. They're Hawke's Bay's team too and this is their base," Paul said as he stamped the ground at Waipatu Marae in Hastings.
The Storm used the marae as their base when they played the St George Illawara Dragons at Napier's McLean Park last year.
Harris' brother-in-law Tane Cooper said he had been waiting 30 weeks for this final.
"I've watched them every week and I knew they would make the final. I know they will sneak in too," he added.
Like Harris' father, his former Tamatea coach Adrian Rowlands, is expecting a close final and predicted a 16-14 win to the Storm.
"It was Storm's defence which gave them their 14-12 win against the Raiders last weekend. They didn't fire on attack ... I'm expecting them to do that this weekend," Rowlands said.
"Looking at form the Sharks have to be the favourites but the Storm won't make the same amount of mistakes the Cowboys did when the Sharks pipped them 32-30 last weekend. It's going to be an epic arm wrestle."
Like Harris' parents, Rowlands, hasn't hounded Harris this week.
"You know what Tohu will say, it's his favourite line. I'm sure all the processes have been put in place."
"What an honour. The first Hawke's Bay player to make an NRL grand final ... I just hope he goes well and wish him all the best," Rowlands said.
"The kid always had it. I remember in 2007 telling Tohu's father, Paul, his son would be an NRL player. Back then Paul knew nothing about league because he was a union man ... now he loves it," Rowlands said.
"Tohu was a young, focused kid ... always helpful and ultra-low maintenance.
"He was a doer, not a talker and a youngster who benefited from plenty of love and support in the home environment," Rowlands said.
Rowlands and Lawrence Te Pou co-coached the Hawke's Bay under-15 team which Harris played in at a 2007 national tournament in Wellington. Harris won the MVP award while catching the eye of the Storm talent scouts at the same time.
In 2008 and 2009 Harris played for Rowlands' Tamatea premier side in addition to playing for the Hastings Boys' High School 1st XV rugby team.
"Tohu could play anywhere in the forwards and anywhere in the backs. He was one of those fellahs you wanted to give the ball to at any opportunity but at the same time we didn't want to put too much pressure on him because he was just 16."
In his last match for the Tamatea premiers at Kirkpatrick Park in 2009, Harris scored three tries and kicked two goals in a 54-12 win against Phoenix after scoring four tries in the reserve-grade curtainraiser which saw Tamatea beat Bridge Pa 42-24.
A month later he started his first two-year contract with the Storm and the following year was named MVP of the club's Toyota Cup under-20 team.
This success and Junior Kiwi selection saw Harris win Ngati Kahungunu's 2010 Junior Sportsman of the Year award.
In 2013 Harris scored a crucial try in the Storm's World Club Challenge win over the Leeds Rhinos in Britain and, after an impressive NRL debut season for the Storm, he made his Kiwis debut in the Anzac test. Last year he shared the Ngati Kahungunu Supreme Sportsperson of the Year award with All Black halfback Aaron Smith.
Harris' former team Tamatea take on Bridge Pa and Omahu meet Te Awhina in today's semifinals of Hawke's Bay's open men's rugby league competition at Bill Mathewson Park, Hastings.