is a Japanese professional shogi player ranked 9-dan. He is a former à Âshà  and Kià  title holder.ãÂÂ
Kubo was born in Kakogawa, Hyà Âgo on August 27, 1975. He learned shogi when he was about four years old, and at the encouragement of a friend of his father soon began playing regularly at the Kobe Shogi Center in neighboring Kobe. The center was managed by shogi professional who became Kubo's shogi teacher after the two played a 19-piece "Naked King" handicap game. In 1986, he advanced to the semi-finals of the 11th as fifth-grade elementary school student, but lost to the eventual tournament winner and fellow future shogi professional Daisuke Suzuki. Later that same year, Kubo entered the Japan Shogi Association's apprentice school at the rank of 6-kyà « under the guidance of Awaji. He was awarded professional status and the rank of 4-dan on April 1, 1993, at the age of 17.
Kubo's first appearance in a major title match came in 2000 when he challenged Yoshiharu Habu for the 26th Kià  title. Kubo advanced to the title match by defeating Masataka Gà Âda 2 games to 0 to win the , but was unable to defeat Habu, losing the match 3 game to 1. The following year, he also challenged Habu for the 49th à Âza title, but lost once again by the same score. In 2007, Kubo once again challenged Habu in the 55th à Âza title match, but was defeated 3 games to 0.
Kubo's first major title victory came in 2009 when he defeated Yasumitsu Satà  3 games to 2 to take the 34th Kià  title. Kubo successfully defended his title for the next two years by defeating Satà  once again 3 games to 2 in 2010 and Akira Watanabe 3 games to 1 in 2011. Kubo, however, was unable to defend his title for the third consecutive year, losing the 37th title match to Gà Âda 3 games to 1.
In 2008, Kubo challenged Habu for the 57th à Âshà  title, but lost the match 4 games to 1. The two met again in 2009 for the 59th à Âshà  title, and this time Kubo was the winner by the score of 4 games to 2. The victory made Kubo a "2-crown" (a player who simultaneously holds two major titles) for the first time. Kubo successfully defended his title the following year by defeating Masayuki Toyoshima 4 games to 2, but lost the 61st à Âshà  title match to Satà  4 games to 1 in 2012. Kubo won the title for the third time in 2017 when he defeated Gà Âda 4 games to 2 to win the 66th à Âshà  title, and successfully defend his title in 2018 when defeated Toyoshima once again 4 games to 2 to win the 67th à Âshà  title. Kubo, however, was unable to defend his title once again the following year when he lost the 68th à Âshà  match to Watanabe 4 games to none.
In SeptemberOctober 2020, Kubo challenged Takuya Nagase for the 68th à Âza title, but lost the match 3 games to 2.
On November 5, 2021, Kubo defeated Shin'ya Satà  in an to become the 25th person to win 800 official games as a professional and was awarded the "Shogi Honor Fighting-spirit Award" as a result.
Kubo is considered to be one of the foremost specialists in the Ranging Rook opening and has been nicknamed the by fellow professionals for his skill at handling such positions. He is also known for his ability to persevere in difficult, even disadvantageous, positions and has been nicknamed the as well. Kubo along with fellow ranging rook specialists Takeshi Fujii and Daisuke Suzuki are collectively referred to as the "Ranging Rook Big Three".
Kubo's promotion history is as follows:
Kubo has appeared in major title matches a total of fifteen times, and has won the Kià  title three times and à Âshà  title four times. In addition to major titles, Kubo has won six other shogi championships during his career.
Note: Tournaments marked with an asterisk (*) are no longer held.
Kubo has received a number awards and honors throughout his career for his accomplishments both on an off the shogi board. These include awards given out annually by the JSA for performance in official games as well as other awards for achievement.
Kubo has finished in the "Top 10" of the JSA's fourteen times and in the "Top 3" twice since turning professional.
Kubo's eldest daughter Shà Âko is a women's professional shogi player.