Kitasan Black was born in 2012. He is by Black Tide out of Sugar Heart by Sakura Bakushin O.
Kitasan Black was awarded Horse of the Year in Japan and Best Older Horse in Japan in 2016 and 2017. Owned by a very famous Enka singer Saburo Kitajima, Kitasan Black earned his first Grade 1 victory in the Kikuka Sho (Japanese St. Leger), the final jewel in Japanese Triple Crown, at 3. He blossomed as a 4-year-old and added two Grade 1 victories to his resume by winning the Japan Cup and the Tenno Sho (spring). He continued his dominance at 5, winning the Grade 1 Osaka Hai, the Grade 1 Tenno Sho (spring), the Grade 1 Tenno Sho (autumn), and the Grade 1 Arima Kinen (Grand Prix).
Kitasan Black entered stud in Japan in 2018. In 2023, Equinox was named the 2023 Longines World's Best Racehorse and was crowned Horse of the Year in Japan, winning all four starts as a 4-year-old: the Group 1 Dubai Sheema Classic, the Grade 1 Takarazuka Kinen, the Grade 1 Tenno Sho (autumn), and the Grade 1 Japan Cup. Equinox's rating of 135 made him the highest-rated horse ever trained in Japan. Equinox was also awarded Horse of the Year in Japan in 2022 after a season in which he won the Grade 1 Arima Kinen (Grand Prix) and the Grade 1 Tenno Sho (autumn). Also in 2023, Sol Oriens produced a scintillating performance to win the Grade 1 Satsuki Sho (Japanese 2000 Guineas). In 2024, Croix du Nord capped off a perfect season in the Grade 1 Hopeful Stakes, staying unbeaten in three career starts and was awarded Best Two-Year-Old Colt in Japan. Also in 2024, Wilson Tesoro captured the Listed (Jpn1) JBC Classic. In 2025, Croix du Nord triumphed in the Grade 1 Tokyo Yushun (Japanese Derby), avenging his runner-up finish in the Grade 1 Satsuki Sho (Japanese 2000 Guineas). Also in 2025, Wilson Tesoro captured the Listed (Jpn1) Mile Championship Nambu Hai.
Among his other best progeny are Gaia Force, who took the Grade 2 St.Lite Kinen, the Grade 2 Fuji Stakes and finished 2nd in the Grade 1 Mile Championship, the Grade 1 Yasuda Kinen, and the Grade 1 February Stakes; Piko Chan Black, who landed the Grade 2 Spring Stakes, Skilfing, who won the Grade 2 Aoba Sho; and Christmas Parade, who landed the Grade 2 Shion Stakes.
Kitasan Black was inducted into the Japan Racing Association Racing Hall of Fame in 2020.