The man still had a firm hold on Morris so Brandon, 15, had to grab the man's jersey, put his arm around him and physically drag him off the driver, with help from Stacey, 16, and Tawhiri, 17.
"It took two of us to get him off but after that he got scared because he thought we were going to do something, and Tawhiri was holding him," Brandon said.
The boys then had to stand between the man and the bus driver to prevent the man from launching himself at Morris again.
The whole incident took only a matter of seconds but all the time the bus was still moving, and once he was free again, Morris was able to concentrate on stopping safely.
He ordered the man off the bus, but he refused.
"[The driver] was fuming and he said 'get off my bus' and he [the passenger] just stood and looked at him and after that we told him to come to the back with us so that they were separated."
The man eventually sat down, and although Brandon got off at Hatepe, Stacey and Tawhiri kept an eye on him until the bus arrived in Tūrangi, where one of the younger passengers' parents alerted police. The boys say they considered calling police, but there is no cellphone coverage along the top of Hatepe Hill.
As the oldest students on the bus, the boys also checked with some of the younger students that they were all right.
"They said they were okay, they were just scared," said Stacey. "It was a quiet ride back to Turangi."
The boys said they didn't know what triggered the passenger's unexpected attack which occurred as the bus was heading up the hill with vehicles coming the other way.
Taupō-nui-a-Tia College principal Peter Moyle, who said the school was very proud of its three boys, found out about the three bus heroes from St Patrick's Catholic School principal Ange Edhouse the next day.
But when he sent for all three of them to come to his office, Stacey and Brandon said they immediately assumed they were in trouble.
"I got a note saying Mr Moyle wanted to see me and I was thinking 'what have I done wrong?", Stacey said.
"I went in by myself," said Brandon.
"And [Mr Moyle] was like 'do you know why you're here?' and I was like 'um ... ' and he said there had been an incident on a bus yesterday and I was 'sweet! I'm all good now!' and then he said he was going to embarrass us up on stage."
The boys were singled out for praise for their bravery and for modelling the school's cornerstone values of respect and responsibility.
John Morshead, the owner of Tūrangi Rentals, which operates Tūrangi Coachlines, complimented the boys' actions and said that they behaved in a very mature manner.
He said the company had decided to no longer offer transport to adults on its school buses because the safety of the children came first.
"We were providing transport for people that needed to go to Taupō to catch an Intercity bus or do shopping or whatever, but we've had to put a stop to adult passengers on the bus."
He said driver was fine afterwards.
"It didn't worry him at all, he just shrugged it off."
Sergeant Te Reipa Morunga of Tūrangi Police said the bus driver had not wanted to take the matter any further so the man involved, a 60-year-old local, had been given an official warning.
