His father, Katsumi, is a banker and an avid golfer. Ryo started playing the game when he was 7, and his father is his primary teacher. Ryo's younger brother and sister also play golf. Known by the nickname "Hanikami Oji" (literally, "Bashful Prince"), he has his own private practice range just about five minutes from his home in Saitama prefecture, which is just outside of Tokyo. The facility is putting in four greens seeded with the same strain of bent grass that's found at Augusta National. The sand in the bunkers was chosen because it's similar to the sand that is at Augusta National. Ishikawa's favorite foods are tonkotsu, a pork and noodle soup and pork cutlet. In addition to golf, Ryo also plays futsal, a form of indoor soccer played on a hard court using a smaller ball with less bounce than a regular one. Ishikawa also skis which helps keep him in shape over the winter. Ishikawa has a contract with Yonex Clubs and according to Reuters, the company spent over a million dollars to develop the driver that he is using. On May 20, 2007, Ishikawa became the youngest winner ever of a men's regular tournament on the Japan Golf Tour by winning the Munsingwear Open KSB Cup at the age 15 years and 8 months. He competed as an amateur and it was Ishikawa's first tour appearance. He finished one shot ahead of Japan's 9th top ranked player at the time, Katsumasa Miyamoto. The highest ranked player on the Official World Golf Ranking who took part in the event was Toru Taniguchi (ranked 86th) who finished T13th, six shots shy of Ishikawa. Taniguchi ranked number 86 in the world after the event. Ishikawa turned professional in 2008 and won another Japan Golf Tour tournament, the Mynavi ABC Championship. By the close of 2008, he had become the youngest ever player to reach the top 100 of the Official World Golf Rankings and also the youngest player to win 100 million yen in a season on the Japan Tour.