After he was born, he was in the intensive care unit for four months and remained in critical condition for two months. As an infant, he lost weight rapidly due to a gastrointestinal disease of unknown cause, and it was dangerous enough that the doctor said the survival rate was 1%. According to the doctor, even if he survived he would still be disabled. He was finally discharged from the hospital when he was seven months old. His mother came up with the idea of making him a child actor because she had been pondering why he was born in this world, and from that, we can see that he was raised with a lot of love. His family consists of his grandparents, father, mother, a sister who is 11 years older than him and two nieces. His grandmother died in 2020.
In 2020, he became the brand ambassador for "Hondashi", alongside Shun Oguri and Hana Sugisaki. While filming the commercial, the atmosphere between the tree veterans was so infectious that the director, for the first time in his career could not say cut, because it was so much fun to watch them.
On May 19, 2020, it was announced that he would start the "25th Anniversary of Debut Project". On June 18, 2020, he created his own Youtube Channel, dubbed "Ryutube". The book titled "Omote Kamiki / Ura Kamiki" was released on September 25. It was made as one part of his debut 25th anniversary project, and it shows the "front side" of Kamikir, as well as the "back side" of him as a regular 27-year-old man. It contains feature words and illustrations by Hayao Miyazaki and Toshio Suzuki. He debuted with his own radio show on All Night Nippon 0 (ANN0) on October 11, 2020, which will air late at night on the weekend.
Kamiki first started to conceptualize his yearly annual calendar in 2020. The theme of the calendar of 2020 being "Birthstones". He thought about the themes himself for each month as well as how to shoot for a year with the motif of the color of the birthstone and the stone language.
He is an enthusiastic amateur photographer and had a dream of putting out a book of photographs of Takeru Sato one day. His dream came true in 2020.