Tosho Boy (Japanese: トウショウボーイ, Hepburn: Tōshō Bōi; 15 April 1973 – 18 September 1992) was a Japanese thoroughbred racehorse and stallion. Tosho Boy was successful as a racehorse, winning 10 of his 15 starts, including some of Japan's most significant horse races, such as the Satsuki Shō, Arima Kinen, and Takarazuka Kinen. Tosho Boy was part of a rivalry called "TTG" between himself, Ten Point, and Green Grass. Tosho Boy was voted both Japanese Horse of the Year and best three-year-old colt in 1976 for his racing successes. After retiring from racing, Tosho Boy was also a significant sire, producing numerous major stakes winners, including Japanese Triple Crown winner Mr. C. B. With his success as both a racer and a stallion, Tosho Boy was elected to the JRA Hall of Fame in 1984.
Background Tosho Boy was foaled on 15 April 1973 at Fujimasa Farm in Shizunai, Hokkaido.更級1992、282-286頁 Tosho Boy's sire was Tesco Boy, a British horse who had most notably won the Queen Anne Stakes in 1966 before being transported to Japan, where he became a leading sire in the 1970s. His dam was an American horse, Social Butterfly, who was a daughter of another successful racehorse, Your Host.江面2015、65頁 Tosho Boy appeared strong even from a young age, and ranch hands at Fujimasa Farm stated they believed that he could win at least one or two of the classic races.長沼1996（『忘れられない名馬100』132-133頁。
During his two-year-old year, Tosho Boy was entered in to the stables of trainer Takayoshi Yasuda to begin race training. He was physically well developed, but Yasuda was concerned about the condition of Tosho Boy's waist area, feeling this would need to develop further before Tosho Boy could begin racing.木村1998、580-581頁。 As such, Tosho Boy did not race as a two-year-old. By December, Yasuda was satisfied with Tosho Boy's racing form, and entered the horse in to his first race, scheduled for the end of January 1976.光栄出版部（編）1995、71-72頁。
Racing career Three-year-old season Tosho Boy's first race was a maiden race at Tokyo Racecourse on the 31 January 1976. Tosho Boy was the favorite entering the race, and lived up to expectations by leading almost the entirely race and taking victory.英雄神話 Dramatic SPORTS Vol.20、11頁。 The race was sometimes referred to as the "legendary maiden race", as the race also featured Tosho Boy's future rival Green Grass and also C.B. Queen, who would later be the dam of Mr. C. B.大川1998、244頁。
Tosho Boy's next races were the Tsukushi Sho in February and the Renge Sho in March, both of which he won with commanding margins of 4-5 lengths. Tosho Boy had become one of the favorites to win the Triple Crown races. The favorite as the classic races approached, however, was Ten Point, who had won in all five of his starts to that point, including already having a major win in the Hanshin Sansai Stakes.山田1998、58・62頁。 In his last races before the classics, Ten Point one, but only by narrow margins, leading some rivals to claim that he was not unbeatable.江面2014、62頁。
Tosho Boy's next race was to be the Satsuki Shō, where he would race against Ten Point for the first time. The race was scheduled for its traditional slot in April at Nakayama Racecourse, but a labor dispute broke out between the Nakayama stable-worker's union and the trainer's association. The union went on strike three days before the scheduled date of the Satsuki Shō, forcing the race to both be delayed to the following week and to be run at Tokyo Racecourse.平岡2005、76-80頁。 The delay caused some disruption to both Tosho Boy's and Ten Point's training schedules, but both arrived at Tokyo Racecourse in good shape. On race day, Ten Point was considered the favorite to win, while Tosho Boy was second favorite. In the race, Tosho Boy broke out from the field entering the straight and was uncontested for the run to the finish, ultimately winning by five lengths over Ten Point.+本1998、28-29頁。 With a time of 2:01.1, Tosho Boy set a new race record, surpassing the record set by Kitano Kachidoki in 1974. After Tosho Boy's dominating victory, media outlets quickly began to a potential Triple Crown winner.冨田1978、137頁。
Tosho Boy's next race was the Tōkyō Yūshun, where he entered as the favorite.|江面1998、143頁。 In the race, Tosho Boy led much of the way, but in the final straight was challenged by Climb Kaiser. Tosho Boy was startled, possibly from contact from Climb Kaiser's jockey Takemi Kaga's whip, and fell fourth lengths back at 200 meters to go. He recovered, but too late to catch back up, and finished second by lengths.江面2014、63頁。 Kaga was investigated post-race for potentially obstructing Tosho Boy, but was cleared and Climb Kaiser retained the win.寺山・古井ほか1998、238頁。 Tosho Boy was rested for roughly a month after the race before being entered in to the Sapporo Kinen. He finished second again. In response, Tosho Boy's owner fired jockey Masahiro Ikegami, and for the fall races hired Yoichi Fukunaga.広見2017、87頁。
Tosho Boy ran the Kobe Shimbun Hai in fall in preparation for the Kikuka-shō. He took victory in the Kobe Shimbun Hai, and entered the Kikuka-shō as the favorite, although there were some doubts about his ability to race the 3000 meter distance. On race day, the track was wet from rain the night before, which cause Tosho Boy to struggle. Tosho Boy took the lead early in the final straight, but was passed almost immediately by Green Grass and Ten Point. Tosho Boy would finish third, five lengths behind winner Green Grass.渡辺1999、266-267頁。 After the race, jocket Yoichi Fukunaga stated that he believed Tosho Boy may have already reached his peak as a racehorse at the Kobe Shimbun Hai and was now in decline.大島1992]]、57-58頁。 One month later, Tosho Boy was entered in to the Arima Kinen. Fukunaga had already committed to riding a different horse for this race, and so Kunihiko Take was hired to ride Tosho Boy. 大川1997、100-102頁。 Despite the recent losses, Tosho Boy was once again the favorite to win. In the race, Tosho Boy held a good position for the entire race and took victory over Ten Point. The result marked the first time in the history of the Arima Kinen that 3-year-old horses took first and second.『優駿』2015年12月号、28頁。 With a time of 2:34.0, Tosho Boy set a new record for fastest 2500 meter race in Japan.
At the end of the year, Tosho Boy was selected as both Japanese Horse of the Year and as the best three-year-old colt.江面2014、64頁。
Four-year-old season Injuries prevented Tosho Boy from racing for much of the first half of 1977. The heavy race load at the end of 1976 caused fatigue injuries, and he was forced to rest. Once recovered, training began in preparation to race the Spring Tenno Sho, but a shoulder injury forced him to miss more time.江面2014、65頁。 At one point, he was scheduled to race against the undefeated Maruzensky in a shorter race at Sapporo Racecourse, but continued leg injuries prevented his entry in to this race as well.阿部1995、88-91頁。
Tosho Boy made his racing return at the Takarazuka Kinen at the beginning on June. Having not raced in over five months, he was only the second favorite, and some observers described his pre-race form as poor.江面1998、146頁。 These concerns over Tosho Boys' form were dispelled during the race. Tosho Boy ran the last 1000 meters in 57.6 seconds – the fastest 1000 meters in Japan at that point – and beat his rival Ten Point by lengths. His next race was the Takamatsunomiya Hai three weeks later, where he won again despite poor track conditions. During the summer, he was rested and did not race again until October. He returned at an open race at Nakayama Racecourse to prepare for the Autumn Tenno Sho - Tosho Boy won by seven lengths.江面2014、66頁。
Tosho Boy was next entered in to the Autumn Tenno Sho. Expectations were high and he was the favorite entering the race again. This race, however, went poorly. Tosho Boy was unable to keep up on the final straight, and fell to seventh at the finish.江面2014、67頁。 After the race, Tosho Boy's owner announced that the Arima Kinen would be his final race before he would be retired to stud. The Arima Kinen was initially set to be a showdown between Tosho Boy, Ten Point, and Maruzensky, but Maruzensky was forced to withdraw due to leg injuries. Ten Point entered as the favorite, having had a strong 1977 season that would lead to him being voted Japanese Horse of the Year. Tosho Boy was second favorite. In the race, Tosho Boy led for much of the distance, but with 200 meters remaining was passed by Ten Point. Tosho Boy began to catch up again at 100 meters remaining, but ran out of time and finished by lengths.中川2020、149頁。 At the time, the battle between Ten Point and Tosho Boy in this race was regarded as one of the greatest races in the history of Japanese horse racing.優駿増刊号 TURF、67頁。『優駿』2003年3月号、17頁。渡辺1999、272頁。
As planned, the Arima Kinen was Tosho Boy's final race, and a retirement ceremony was held on 8 January 1978 at Tokyo Racecourse.1998、249頁。
Racing record Tosho Boy competed in 15 career races, winning 10. Date Race Distance Surface Track Finish Field 1st Place (2nd Place) 31 Jan 1976 Three Year Old 1400m Turf Tokyo 1 18 (Royal Seikan) 22 Feb 1976 Tsukushi Sho 1400m Dirt Tokyo 1 12 (Hoyo Silver) 20 Mar 1976 Renge Sho 1800m Turf Nakayama 1 8 (Keishu Ford) 25 Apr 1976 Satsuki Shō 2000m Turf Tokyo 1 15 (Ten Point) 30 May 1976 Tōkyō Yūshun 2400m Turf Tokyo 2 27 Climb Kaiser 11 Jul 1976 Sapporo Kinen 2000m Dirt Sapporo 2 10 Great Seikan 3 Oct 1976 Kobe Shimbun Hai 2000m Turf Hanshin 1 9 (Climb Kaiser) 24 Oct 1976 Kyoto Shimbun Hai 2000m Turf Hanshin 1 8 (Climb Kaiser) 14 Nov 1976 Kikuka-shō 3000m Turf Kyoto 3 21 Green Grass 19 Dec 1976 Arima Kinen 2500m Turf Nakayama 1 14 (Ten Point) 5 Jun 1977 Takarazuka Kinen 2200m Turf Hanshin 1 6 (Ten Point) 26 Jun 1977 Takamatsunomiya Hai 2000m Turf Chukyo 1 9 (Center Good) 23 Oct 1977 Open 1600m Turf Nakayama 1 6 (Kane Kofuji) 27 Nov 1977 Tenno Sho (Autumn) 3200m Turf Tokyo 7 12 Hokuto Boy 18 Dec 1977 Arima Kinen 2500m Turf Nakayama 2 8 Ten Point
Stud career Tosho Boy was retired to stud at Hidaka Light Stallion Agricultural Cooperative's Urakawa Stud Farm in Hidaka, Hokkaido.江面1998、147頁。 The purchase of Tosho Boy for breeding came at a high price of ¥250 million, with his owner retaining Tosho Boy's seed stock for three years and permanent breeding rights to three horses a year.吉沢1992、49頁。
Initially, Tosho Boy's popularity as a sire was limited, and he was mated with mares with less desirable pedigrees.吉沢1992、50頁。 This changed in 1982, when Tohso Boy's son Daizen King won the Hanshin 3-year-old Stakes and was named best two-year-old colt. The same year, Tosho Boy was named the leading sire in Japan.山本1998、34頁。 The following year, another of Tosho Boy's sons, Mr. C. B., became the first horse to win the Japanese Triple Crown in 19 years.吉沢1992、48頁。 In 1984, Tosho Boy was entered in to the JRA Hall of Fame. After these successes, Tosho Boy became a popular sire throughout the 1980s and in to the early 1990s, producing numerous graded stakes winners. He was referred to as "Help Boy" by smaller breeding farms, as they claimed that a single horse sired by Tosho Boy could pay off a farm's entire debt.吉沢1992、52頁。 Due in part to his success, a previously held notion that Japanese domestic horses were inferior as sires to foreign-born sires was gradually dispelled, and the popularity of having other successful Japanese racing horses increased.吉沢1992、51頁。
Notable progeny Tosho Boy's major stakes winners include:
c = colt, f = filly, g = gelding; horses in bold won at least one Grade 1 event.