Matt Brown, founder of She Is Not Your Rehab, told The Hits' Jono and Ben that his mother became emotional when he read her Johnson's letter in response to a viral video featuring his son Angelou.
Angelou Brown, who is only 5 years old, sent the Hollywood actor a message and a gift, in a bid to help spread the anti-violence message to men around the world.
She Is Not Your Rehab is a movement that empowers men to address their domestic violence issues and encourages family and communities to treat our women better.
Five days after the boy's video went viral, "The Rock" posted his response yesterday.
"Just watched and this one just sat me down. A bit emotional watching this 5-year-old little boy speak to me," the actor posted, alongside young Angelou's video. "The Rock" added a crying emoji to his caption, which then became an open letter to the 5-year-old boy from Christchurch.
"Angelou, it's Uncle Rock. Yes, I'm your 'uncle' because of course, all us Samoans are related," he began.
"I'm very proud of you, son," Dwayne Johnson continued.
"You don't understand yet, because you're too young but just know how courageous and inspiring you are to myself and our aiga (family), but now - to the world."
"The Rock" singled out the work the boy's father does with the "She is Not Your Rehab" group, as well as the boy's nana.
"I admire your father, greatly for standing up and creating @sheisnotyourrehab. And to make sure his mom - your Nana - will never be forgotten. Encouraging men all over the world to treat our women with respect, love and most importantly, violence-free," he said.
"The way you sit in your Nana's arms as she speaks to you is the exact same way I would sit in my grandma's arms when I was your age, while she said her prayers in Samoan to God, and then she'd talk to me afterwards just like she talks to you.
"She would tell me the exact same things your Nana is telling you. Listen to her. And always remember her words," the actor advises the boy.
"You stay strong, Angelou and keep listening to your Nana and your dad. One day you will become the leader of your aiga and also a leader the world will admire."
The video of Angelou was first posted online on the "She is Not Your Rehab" page last week.
"Dear Mr Rock, my name is Angelou Brown and I am 5 years old. I live in Christchurch, New Zealand," he starts off.
"My dad is Samoan so I'm pretty sure you're his cousin. And since you're part of the aiga (family), I thought I'd send you a gift. It's a T-shirt.
"Not just any T-shirt. This T-shirt my dad and my uncles wear to encourage other men to treat girls well."
"Men all around New Zealand, the Pacific, and even the whole wide world because his mum, my nana, had a sad life when they were growing up with lots of fights at home.
"It was sad for my dad to watch her get hurt a lot. And she had to go away lots to many refuges.
"My dad says it's his mission to help other men to heal so their wives don't have sad lives like Nana did."
Angelou then says many men look up to The Rock and hopes if the movie star and former wrestler can spread the message then it'll help troubled men turn a corner.
"These are what these T-shirts are, because I think you're the strongest man on the planet that many men look up to.
"If you wear this T-shirt then I think they will listen to you and we can help houses everywhere be violence-free.
"I hope it gets to you even if you live on an island far away.
"From our aiga to yours, we send you our alofa. Love Angelou."
"The journey of healing is very painful because you sometimes have to revisit some of that past trauma," Brown said.
"You have to remind yourself that you are no longer that young child, that you are older and wiser and have more options and opportunities to get help."
Brown said he witnessed his mother being "subjected to abuse I thought would kill her" and told Jono and Ben that he was still working as an adult to understand what he saw, saying that "children are awesome recorders but terrible interpreters".
Angelou's father and founder of She Is Not Your Rehab, Matt Brown, told the Herald last week he decided to reach out to Johnson in the hope his mana in the Pacific community would make men stand up and listen.
"Our goal with all our mahi (work) and messaging is to change the narrative around domestic violence.
"We ask ourselves how we can engage people to have hard conversations in palatable ways. For White Ribbon Day this year my own mother's story was close to my heart and I know hers is similar to many other Polynesian women, I feel it's time for Pacific men in our communities to stand up and say no more.
"There's no one better to lead that then The Rock himself. For many of us he was a superhero growing up so I thought if he would support this then Polynesian men would listen."
Brown and his movement's ultimate goal is for "Aotearoa to become violence-free".
