On May 26, 2014, Otosaka made his NPB debut, and notched his first career hit, a solo home run against the Chiba Lotte Marines, in one of only two at-bats on the year.

[2] In 2018, Otosaka played in 73 games for Yokohama, posting a .204/.290/.226 slash line with no home runs and 7 RBI.

[citation needed] On April 29, 2022, Otosaka signed with the Bravos de León of the Mexican League.

[6] He appeared in 40 contests for Saltillo down the stretch, hitting .374/.469/.456 with 2 home runs, 15 RBI, and 12 stolen bases.

On November 8, 2024, Otosaka was traded to the Tecolotes de los Dos Laredos of the Mexican League.