He entered Kyushū Gakuin Integrated High School where he became their team's regular first baseman and cleanup hitter.

[6] In June, he got awarded League MVP of the month for batting .315 and driving in 14 runs, last accomplished by a Swallows rookie in 2011 by Tetsuto Yamada.

This made him the youngest Swallows player to start in the season opening game at 19 years old, beating the previous record of 21 year-old Seikichi Nishioka in 1958.

[20] Murakami won the Central League MVP award following the 2021 season by hitting the league-leading 39 home runs, driving in 112 RBIs and drawing 106 walks while slashed .278/.408/.566.

[21][22] In the Japan Series, Murakami hit two home runs to help the Tokyo Yakult Swallows capture their first title after 20 years.

[23][24][25] He also became the first person who plays offense to win the NPB Triple Crown since Nobuhiko Matsunaka of the Fukuoka Daiei Hawks in 2004, and the first by a Central League player since Randy Bass of the Hanshin Tigers in 1986, and the youngest player to win the Triple Crown, at 22 years, eight months, and one day old at the conclusion of the 2022 regular season.

After struggling during most of the tournament and going 0-for-4 with 3 strikeouts in the semifinal against Mexico, Murakami hit a walk-off two-run double to help Japan prevail 6–5.

[28] In the final against the defending champion USA, Murakami led off the bottom of the second inning with a first-pitch home run off Merrill Kelly to tie the game.