"[Introducing a rugby league side] gives them a chance to play for the school when they would not have had the opportunity before."
Mr Grinter said the school would look to continue with rugby league in the future, starting with next week's tournament.
Boys' High is considered by many as one of the best rugby union schools in the country, something Mr Grinter believed would not change with the introduction of a new code.
He said the national secondary school tournament was only a one-off tournament each year and would not seriously interrupt players in the first XV.
Team manager Kimiora Webster said it was good to see players joining the team who had not represented the school before.
"A lot of the boys have never represented the school in sport and have just come to join in. So it has opened it up to a different group of boys," he said.
"It will be a good experience for all of us, especially for the boys who are new to league."
The Rotorua' Boys High School team will be co-captained by WaiCoa Bay Stallions and New Zealand U18 player Te Toiroa Tahuriorangi, 18, and Ngarohi McGarvey-Black, 17.
The two players said it was an honour to captain the school's first-ever rugby league team.
New Zealand Rugby League football and community general manager Dain Guttenbeil said it was great to have the school on board.
"The NZRL is pleased to see Rotorua Boys' High School on board and it presents a strong example that both rugby codes can co-exist within secondary school sport, as Auckland Grammar demonstrated last year."
He said for some young players rugby league could be a career option, so it was important to give players a good chance to play.
"The intention of the NZRL is to provide an opportunity for all New Zealanders to experience rugby league and represent their school, regardless of where they live," he said.
"There are 16 professional rugby league and 10 professional rugby union clubs in Australasia. Progressing and playing for any of them is a success for our youth."
Twenty-four schools will take part in the Rugby League National Secondary School Tournament next week. Rotorua Boys' High School will compete in the second tier - the developing schools competition. Their first match will be against Southland Boys' High School on Monday.