[1][2][3] His family moved to France when he was two years old and then returned to Misato in Saitama Prefecture, Japan when he was about five.
His middle ear, however, became inflamed from swimming, and his doctor advised his parents to limit his playing to indoors for a while until it healed.
[11][12][13] In June 2017, Sasaki ended Sōta Fujii's record-breaking winning streak.
[15] The following year the two met again in the championship game of the 73rd NHK Cup tournament, but this time it was Sasaki who came out victorious.
[23] Sasaki has finished in the "Top 10" of the JSA's year-end prize money and game fee rankings [ja] once: 4th with JPY 29,000,000 in earnings in 2024.