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Dear Yumiko Sato,
Thank you for posting your request on History Hub!
According to the USMC Historical Division Monograph titled Saipan: The Beginning of the End by Major Carl W. Hoffman (1950) pp. 268-269, there were 3,144 U.S. servicemen (both Army & Marine Corps) who were killed or died of their wounds and 10,952 that were wounded in action. We were unable to verify the number of Japanese casualties.
To verify how many Japanese casualties there were, we suggest that you contact the Military History Department, National Institute for Defense Studies, 2-2-1 Nakameguro, Meguro-ku, Tokyo 153-8648, Japan. The web site is https://www.nids.go.jp/english/index.html.
We hope this information is helpful.