In the 2018 season, Masuda played in the Western League of NPB's minor leagues.
On September 28, 2019, Masuda debuted in the Pacific League against the Orix Buffaloes.[2] In 2019, he played 2 games in the Pacific League. On November 27, Masuda underwent surgery on his right wrist.[3]
In 2020, Masuda spent the season rehabilitating his right wrist and was unable to play in the Pacific League.[4]
In 2021 season, Masuda never got a chance to play in the first league.
In 2022 season, Masuda was registered in the first team registration on July 17.[5] He recorded his first hit that day, a home run, against the Chiba Lotte Marines.[6] While his main players tested positive for COVID-19 and were out for rehabilitation, he was active, hitting the first two runs hit of the game on August 26 against the Hokkaido Nippon-Ham Fighters, And He was a member of the "Chikugo Hawks" and supported the team until the main players returned. (a nickname given to the younger reserve players. Chikugo is the name of the place where the Hawks farm team is located.)[7] He finished the regular season with a .256 batting average, one home run, and 6 RBI in 15 games.
In 2023 season, Masuda finished the regular season in 35 games with a batting average of .182, a one home runs, a RBI of 3, and a one sacrifice bunts. On October 22, the Hawks announced release him.[8]