Nishiyama was promoted to the rank of apprentice professional 1-dan in January 2014, becoming just the second woman to achieve that rank after Kana Satomi. Later that same year in September 2014, she became the second woman to be promoted to the rank of apprentice professional 2-dan. Nishiyama was 19 years and 2 months old when she was promoted, thus breaking Satomi's record of 21 years and 4 months. In December 2015, Nishiyama was promoted to the rank of apprentice professional 3-dan, thus beoming the second woman to achieve such a rank. At age 20 years and 5 months, she also broke Satomi's record of 21 years and 9 months. With Satomi having to leave the 3-dan league in 2018, Nishiyama is now the only woman competing in the league. Nishiyama finished the 66th 3-dan League in third place with a record of 14 wins and 4 losses. Going into the last day of league play, Nishiyama was in provisional third place with a record of 12 wins and 4 losses, trailing Hiroki Taniai and Shinichirō Hattori. Since Nishiyama's league seed was the lowest of the three, she needed to win both of her games and finish at least one game ahead of one of the other two to obtain automatic promotion to the rank of :Professional shogi player#Professional players|professional 4-dan. Taniai lost one of his two games, but Hatori and Nishiyama won both of theirs which meant that all three finished league play with the same record. Although Nishiyama missed out on being promoted due to her lower seed, her result was good enough to earn her a promotion point for future league play and means she needs only one more promotion point to qualify for full-professional status.
Nishiyama has appeared in women's professional shogi major title matches a total of four times. Her first appearance came in 2014 when she challenged fellow apprentice shogi professional Momoko Katō for the 4th title, but she lost the match 3 games to none. Nishiyama and Katō met again in May 2018 in the 11th and its Jo-Ō title. Nishiyama defeated the defending Jo-Ō Katō 3 games to 1 to win her first major title match. Nishiyama's victory also made her the second apprentice professional after Katō to win a women's professional shogi major title. Nishiyama successfully defended her Jo-Ō title the following year when she defeated women's professional shogi player Kana Satomi 3 games to 1 in May 2019. Nishiyama challenged Satomi for 41st title in OctoberNovember 2019. She won the first game of the match, lost the second, but won the deciding third game to capture the title 2 games to 1. The victory made her a Professional shogi player#Women's tournaments for the first time. In OctoberDecember 2019, Nishiyama and Satomi met in the 9th Women's Ōza title match, their third major title match in six months. Nishiyama won the match 3 games to 1 to capture another of Satomi's titles and also become a 3-crown title holder for the first time. In June 2020, Nishiyama successfully defended her Jo-Ō title by defeating Momoko Katō 3 games to 2 to win the 13th Women's Myavi Open Tournament.
Promotion history
Nishiyama's promotion history is as follows.
2010: 6-kyū
2014, January: 1-dan
2014, September: 2-dan
2015, December: 3-dan
Awards and honors
Nishiyama won the Japan Shogi Association’s Annual Shogi Award for “Women’s Professional Game of the Year” for the 2019 shogi year.