[3] Per Yamamoto, he first caught the attention of scouts when they came to the ballpark to watch his teammate Kodi Medeiros pitch.

[2] In the summer before his senior year, he committed to play college baseball at Arizona on a full scholarship[4] over competing offers from Utah, Oregon and Loyola Marymount.

[8] On January 25, 2018, the Brewers traded Yamamoto, Isan Díaz, Lewis Brinson, and Monte Harrison to the Miami Marlins in exchange for Christian Yelich.

[14][15] He pitched seven shutout innings with five strikeouts and earned the win as the Marlins defeated the St. Louis Cardinals 9–0.

[21] On April 5, 2022, Yamamoto was designated for assignment to create room on the roster for Chasen Shreve, whose contract was selected.

Yamamoto made 24 appearances split between the High-A Brooklyn Cyclones, Double-A Binghamton Rumble Ponies, and Syracuse, accumulating a 3-2 record and 6.00 ERA with 57 strikeouts across 54 innings.

[24] On July 10, 2023, Yamamoto became the head coach of the William T. Dwyer High School (Palm Beach Gardens, Florida) baseball team.

"[2] During a 2019 start, Yamamoto wrote a message on his hat in support of the Thirty Meter Telescope protests.