South Korean grandfather Chan Jae used to live near his grandsons in Brazil and would drive them to school every day.
When they moved overseas, he missed them terribly. Allan and Arthur seemed so very far away in South Korea, and another grandson, Astro, was also a plane flight away in New York.
Then the 75-year-old's wife and son came up with an idea to help him stay in touch with the boys using the power of social media.
Jae draws pictures by hand for his three grandsons, which are then shared on Instagram.
His Instagram account, Drawings For My Grandchildren, has more than 102,000 followers, with the number rapidly climbing since his son Ji Lee, a creative at Facebook and Astro's father, told the story via a Facebook video.
"My father was retired and spending time with my nephews, like driving them to school, was a huge part of his day," he told the BBC.
"After they left, he had nothing to do and that scared my mother and me.
"We were very worried that he would age quickly without having anything to do and would become depressed."
His "quiet reserved" father was initially very resistant to learning about the new technology and hated the idea, but over time he has embraced the new form of communication.
"Now he uses different editing tools and can even understand hashtags, so that was revolutionary," Lee said.
Each post is translated into English, Korean and Portuguese, with animals, superheroes, nature, Korean culture and three grandchildren common themes of his work.
Thousands of Facebook users have written about how Jae's story has touched and inspired them. To Lee, who has been on Instagram since early 2015, it has been one of most rewarding part of the project.
"There were hundreds of messages saying our story inspired them to speak to their own aging parents. It takes a lot of patience and empathy to teach someone like my father to see the meaning and joy of starting a project using a new technology, but for us it has been incredibly rewarding and transformational."