Early years Taro started playing tennis when he was 7 years old. He played the singles rubber, but lost to
Lukáš Rosol in a five-setter and
Jiří Veselý. Daniel qualified for the
2014 US Open to make his Grand Slam main-draw debut, losing to fifth seed
Milos Raonic in the first round. The next week, he reached the final at the
Seville Challenger, where he was defeated by top seed
Pablo Carreño Busta.
2015: Top 100 After competing in the ATP events of Montpellier and Casablanca, Daniel defeated
Filippo Volandri to claim his first ATP Challenger Tour title in
Vercelli. He qualified for the
2015 French Open, losing to 32nd seed
Fernando Verdasco in the first round. In July, Daniel won the
Fürth Challenger, defeating top seeds
Blaž Rola and
Albert Montañés. At
2015 Davis Cup World Group play-offs against Colombia, Daniel won the first Davis Cup match of his career, beating
Alejandro Falla in the last tie. His victory completed a come-from-behind victory against Colombia to remain in the World Group for 2016. In October, he qualified for the
Valencia Open, and reached the second round, before losing to sixth seed
Guillermo García-López. He completed the 2015 season with his third Challenger title in
Yokohama, winning over his countryman
Go Soeda in the final. He entered the top 100 in the ATP rankings for the first time at world No. 93 on 23 November 2015.
2016: Masters debut and win, Major first win, Olympics debut Daniel received direct entry to the main draw of the
2016 Australian Open, losing in the first round to
Lukáš Rosol in five sets. In February, he reached the second round of the
Open Sud de France before losing to eighth seed
Marcos Baghdatis in straight sets. At
2016 Davis Cup World Group first round in Birmingham, Japan faced defending champion
Great Britain. He was defeated by world No. 2
Andy Murray in straight sets; Japan lost 1–3. Daniel qualified for the
Monte-Carlo Masters to make his
ATP World Tour Masters 1000 main-draw debut. He beat
Adrian Mannarino in straight sets to reach the second round, where he lost to 12th seed
Dominic Thiem in three sets. He then competed at
Bucharest and
Estoril, reaching the second rounds in both tournaments. In the
2016 French Open, he advanced to the second round of Major tournaments for the first time in his career when his opponent
Martin Kližan had to retire from injury in the fifth set. He lost to third seed and defending champion
Stan Wawrinka in straight sets despite having two set points in the first set and being up a break in the third. He next competed in the
2016 Wimbledon Championships, losing in the first round to
Juan Mónaco in four sets. Daniel competed in the Olympics, where he defeated the No. 14 seed
Jack Sock in straight sets in the first round. Daniel then beat
Kyle Edmund of Great Britain before losing to
Juan Martín del Potro, despite having won the first set.
2017–18: First Masters third round and ATP title, Top 65 debut Daniel reached the second round of the
2017 US Open where he lost to
Rafael Nadal in four sets. In March at the
2018 Indian Wells Masters, Daniel qualified for the main draw and defeated
Cameron Norrie and world No. 13
Novak Djokovic in three sets to reach the third round. In May, he made his first ATP final at the
2018 Istanbul Open, where he played Tunisian
Malek Jaziri, also in his first final. Daniel beat Jaziri 7–6 6–4 to win his first ATP title. Daniel climbed to his career high ranking of No. 64 on 27 August 2018. He finished the 2018 season ranked No. 77.
2019–21: Out of top 100, Olympics Daniel, as a
lucky loser, reached the semifinals in
2021 Serbia Open in Belgrade, where he beat
João Sousa, 7th seed
John Millman and
Federico Delbonis, but lost to second seed and eventual champion
Matteo Berrettini.
2022: Grand Slam third round, back to top 100 After winning through
2022 Australian Open qualifying, Daniel made it to the third round of a Grand Slam for the first time in his career, beating
Tomás Barrios and former finalist
Andy Murray in the process. He lost to 10th seed
Jannik Sinner in the third round. At the
2022 BNP Paribas Open in Indian Wells in March, having beaten him at Melbourne, Daniel lost to Andy Murray, giving the Scot the 700th match win of his career on the ATP Tour. Daniel reached back-to-back quarterfinals in
Belgrade, beating
Dušan Lajović and
Holger Rune. He lost to second seed and eventual champion
Andrey Rublev in straight sets. He finished the 2022 season ranked No. 92.
2023: Best season: First Top 10 win, Two consecutive Masters third rounds Ranked No. 125 at the
Mexican Open, Daniel reached the quarterfinals as a qualifier defeating second seed
Casper Ruud for his first top 10 win of his career. At the
2023 BNP Paribas Open he defeated
Roberto Carballes Baena and 20th seed
Matteo Berrettini to reach the third round of a Masters as a qualifier for the second time at this tournament and in his career. As a result he returned to the top 100. He received a wildcard into the
2023 Miami Open where he defeated
Arthur Rinderknech who retired in the first round. Next he defeated 13th seed
Alexander Zverev to reach back-to-back Masters third rounds in two weeks. He finished the 2023 season ranked No. 75, his highest year-end career ranking.
2024: Second ATP final, top 60, Japanese No. 1 Taro reached his second ATP final at the
2024 ASB Classic in Auckland, New Zealand defeating top seed
Ben Shelton becoming the first Japanese finalist at the tournament. As a result he reached the top 60 at world No. 58 in the singles rankings on 15 January 2024. He became the No. 1 Japanese male player. He lost to qualifier
Alejandro Tabilo in straight sets. ==ATP career finals==