Dear Mr. Emoto,
Thank you for posting your request on History Hub!
United States ports were not required to maintain departure passenger lists. As passenger names were occasionally listed in a newspaper for the departure port as traveling on a certain ship on a certain date, we suggest that you search the local newspaper archives for mention of your grandfather’s passage.
We also suggest that you search Japan Passenger Lists, 1893-1941 and contact the Japan Center for Asian Historical Records (JACAR) and the Japanese Ministry of Foreign Affairs Diplomatic Archives for any arrival information regarding your grandfather for the dates that you seek.
We hope this is helpful. Best of luck with your family research!
Thank you so much for your response to my question. I really appreciate it.