A mum introduced her autistic son to his new assistance dog for the first time - and his sweet reaction touched the hearts of people across the world.
Kai was diagnosed with autism at the age of four, and his unique sensory preferences mean that he doesn't always like to be touched.
But that wasn't the case when he met golden Labrador Tornado, who he quickly embraced with a huge hug.
Mum Shanna Niehaus, 36, from Florida, was captured on camera silently crying behind the pair, and soon went viral online.
Five years later, Shanna is sharing how six-year-old Tornado has changed her son's life in every way.
She told The Mirror : "Tornado has been an absolute joy to welcome into our family and my heart is filled to the brim every single day watching my son coexist with his best friend in the whole world.
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On October 17, 2016, Shanna and Kai travelled from Tokyo - where their family had been temporarily living - to Ohio, to meet Tornado for the first time.
Shanna had raised almost £11,500 to help 4 Paws for Ability partially cover the cost of training Tornado, and raised an additional £16,800 for travel and expenses.
Just hours after meeting each other, Kai surprised everyone and laid on Tornado to feel his heartbeat.
Shanna was so taken aback, she began to cry - but covered her mouth so she wouldn't make a sound and potentially distract Kai.
"I definitely did not expect the moment to be so emotional," Shanna said.
"When Kai and Tornado met earlier in the morning, things were exciting and fun. The viral photo moment of Tornado, Kai, and I together occurred later.
"The calmness of the afternoon had made room for me to reflect on all I had done to get us to that point, and my emotions sort of just came through."
Kai had always been drawn to dogs and had asked several times if he could have one as a pet.
Finally, his dream came true, and it was worth every single penny.
"Because Kai is autistic, his sensory processing is different than many other children. Kai has his own unique sensory preferences, and he enjoys hugs on his own terms," Shanna said.
"When I hug and touch my son, I do so with his consent and with consideration for how his sensory processing is operating at any given moment."
The duo have since grown closer and closer over the years, and Shanna says Tornado has "unconditional love and support for him - through absolutely anything".
"To Tornado, it doesn’t matter if Kai makes a strange noise, or wears silly clothes, or looks different than other kids. Tornado adores Kai and supports him regardless of what anyone else think," Shanna said.
"He provides Kai a unique type of safety and security for Kai to be authentically himself, without judgement or expectations. At the end of the day, isn’t that what we all want?"
Day to day, Tornado helps Kai navigate the world with autism and reduces societal pressures.
"Outside of his formal duties, Tornado provides Kai with acceptance, partnership and a very best friend," Shanna said.
Tornado has about two working years left before he retires, and Shanna will begin fundraising for his replacement dog later this year.
"Tornado will continue to be a dearly cherished member of our family for the duration of his life," she said.
"I'll be eternally grateful to 4 Paws for Ability for bringing him into our lives, and for bringing a furry spark of life for my son."
You can keep up-to-date with Kai and Tornado's friendship on their Facebook page.
Do you have a dog story to tell? Contact nia.dalton@reachplc.com.
