Baba started the Far East Cup for the first time in Pyeongchang in December 2014 , finishing seventh over 10 km classic and second over 15 km freestyle. At the Junior World Ski Championships in Almaty in 2015 , he ran to 62nd place in sprint, 25th place over 10 km freestyle and ninth place in skiathlon . His best placings at the Junior World Ski Championships 2016 in Râșnov were 23rd place over 15 km freestyle and 12th place with the relay. In the 2016/17 season he achieved four top ten finishes, including two second places, ninth place in the overall ranking of the Far East Cup. His best results at the 2017 Winter Universiade in Almaty were sixth place in the pursuit and fourth place with the relay. At the Winter Asian Games in Sapporo in February 2017 , he won the silver medal in the 15 km freestyle and the gold medal with the relay. At the beginning of the 2017/18 season he completed his first World Cup race in Davos , which he finished in 72nd place over 15 km freestyle. In the further course of the season he reached with three second places and a third and first place, the second place in the overall ranking of the Far East Cup. At the U23 World Championships 2018 in Goms , he came in 55th place in sprint, 20th place over 15 km classic and 14th place in skiathlon. At the end of the season he took 65th place at the World Cup final in Falun . In the following season he took three wins in the Far East Cup and thus achieved fifth place in the overall standings. At the U23 World Championships in Lahti in 2019 , he finished 60th in the sprint, 16th in the 15 km freestyle and fifth in the 30 km mass start race. In February 2019 he ran at the Nordic World Ski Championships in Seefeld in Tyrol on 28th place over 15 km classic, 24th place in the skiathlon and 21st place in the 50 km mass start race. The following month, he won the gold medal in the 30 km mass start race at the 2019 Winter Universiade in Krasnoyarsk . After finishing 36th in the Ruka Triple at the beginning of the 2019/20 season, he scored his first World Cup points in Lillehammer with 21st place in the skiathlon. This was followed by two wins in the Far East Cup in Otoineppu and 40th place on the ski tour at the end of the season.
Japan