Hashimoto competed at the World Championships in Stuttgart, Germany, where his team placed third all around.[6] On the pommel horse, he finished in 9th place, and on the horizontal bar, he finished in 4th place.
2021
Hashimoto's breakthrough arrived when he became the national all-around champion. His score of 88.532 was the highest of 2021 until being surpassed by Zhang Boheng's 88.565 result at the Chinese Olympic Trials. One month later, Hashimoto participated in NHK Trophy, and despite only achieving the second highest score of the night, he still won the title because the tournament also used the scores of All Japan AA Championships for the final results. In June, Hashimoto achieved another victory at the All Japan Event Championships. With such impressive performances, he was later selected in Japan men's national gymnastics team competing at the Olympics.
At the Olympics, Hashimoto competed in team event with Kazuma Kaya, Takeru Kitazono, Wataru Tanigawa & won the silver with only 0.103 points behind the ROC team.[7][8][2] He also won two gold medals in all-around and horizontal bar,[2] making him the most successful male gymnast in Tokyo with three medals — two golds and one silver. Being just 10 days before turning 20, Hashimoto also became Japan's second youngest and one of only two teenage male gymnasts in history to accomplish that feat after Kenzō Shirai, who won team gold six days younger in 2016. This would also include by default Hashimoto becoming the youngest Japanese gymnast to win Olympic gold on the all-around and horizontal bar events. In the men's individual floor exercise and pommel horse event finals, Hashimoto would place eleventh and ninth.
At the 2021 World Championships in Kitakyushu, Hashimoto was the top qualifier on the men's individual all-around and horizontal bar, but only earned two silver medals on those events. He also placed fourth in the parallel bars, and withdrew from floor and pommel horse, despite qualified for the finals.
2022
At the 2022 All-Japan all-around championships in late April, Hashimoto successfully defended his title, leading in both qualification & final. He also won the NHK Trophy, despite multiple falls in pommel horse & horizontal bar. In June, Hashimoto participated in All-Japan event championships, competing in floor, pommel horse, parallel bars & horizontal bar. He had previously qualified in rings but withdraw later. In floor, he won the bronze, while in pommel horse & horizontal bar finals, he made several falls & only achieved 7th & 6th place respectively. In parallel bars, he made mistakes at the qualification & did not advance to the final.
Later in late August, Hashimoto achieved the highest AA score of the year, getting 88.331 at the All-Japan Student Championships. He also won every gold & silver at every event.
Hashimoto was selected to represent Japan at the World Championships in Liverpool after winning the NHK Trophy. Despite a fall at the pommel horse in qualification, he still made it to AA, FX & HB finals. In men's team final, Japanese men made a few serious mistakes & ended up with the silver, losing the title to China. However, Hashimoto managed to win the all-around championship, reversing the 2021 result. He was also the runner-up in floor & horizontal bar, with only 0.033 & 0.100, respectively, behind the eventual champions.
Hashimoto and his teammates from Juntendo University failed to defend the title at the All-Japan Team Championships, where he made serious falls in his pommel horse and parallel bars routines, as well as underperformed in floor, vault and horizontal bar. His all-around score was only 81.364, the lowest since 2019.
2023
Hashimoto started the 2023 season with 2 gold and a silver at the 2023 DTB Pokal Stuttgart, where he won the Mixed Cup and horizontal bar events, while being the runner-up at Men's Team Challenge. Later in April, he successfully defended the All-Japan All-Around Championships crown and became the 10th male gymnast to win the title 3 times. In May, he also won the NHK Trophy for the third consecutive year, despite the falls on pommel horse and horizontal, as well as underperforming the floor exercise routine. At the All-Japan Event Championships in June, Hashimoto was set to compete in floor, pommel horse and horizontal bar. His rings and parallel bars scores at All-Japan All-Around Championships would have been enough to be qualified, but a change of qualification rule only allowed only top 8 in AA qualification and final nights, and the other spots would be determined at tryout round 3, in which he did not participate. In pommel horse, Hashimoto ranked 11th in qualification, while in floor and horizontal bar, he was qualified directly to the final as being World Championships runner-up, but withdrew from floor and fell off the high bar, resulted in ranking last.
At the Summer Universiade in August, Hashimoto delivered one of the best performed in his career, scoring 88.698 in men's team final and qualified for floor, pommel horse, parallel bars and horizontal bar finals. However, some mistakes from his teammates dragged Japan to 2nd place. During the AA final, Hashimoto, who ranked 1st in qualification, clashed his head as he fell from the pommel horse and was forced to withdraw from the rest of the competition. About 2 weeks after the incident, he recovered quickly to compete at the All-Japan Student Championships. Despite a fall on horizontal bar, he managed to win the team and all-around titles, as well as ranking 1st in vault & parallel bars.
Hashimoto participated in the World Championships with a rough start. Mistakes from pommel horse and vault routines made him only ranked 3rd in all-around qualification, and would not have been able to advance to final as the first 2 ranks were his teammates. However, as the team already had prior discussion, Kazuma Kaya gave up his spot to him. In men's team final, Hashimoto, together with Kenta Chiba, Kazuma Kaya, Kazuki Minami and Kaito Sugimoto won the gold for Japan for the 1st time since 2015. He later defended his World crown in all-around and won his first world championships gold medal in horizontal bar, with one of the best routines in his career. With this results, Hashimoto is now ranked among male gymnasts as 2nd most all-around gold medals and 3rd most all-around medals at the World Championships.
His two older brothers, Takuya and Kengo, who competed in artistic gymnastics at the club- and university-level in Japan, inspired Hashimoto to begin gymnastics at age seven at the Sawara Junior Club.[17]
Hashimoto has received two awards. In 2019, he received the Excellence Award at the 2019 NHK Cup. In 2020, he was given the Road to 2020 Olympic Encouragement Award at the TV Asahi Big Sports Awards.[17]
