Using Outlook for Android in business environments for email and scheduling
Dear Michael Cook2
Welcome to Microsoft Community.
According to your description, you have set your phone's language to English, but your phone's Outlook shows Japanese, right?
For this issue, you can try to follow the following ways to try if you can exclude it:
Outlook manually change the language:
You can try to manually change the language to another language in mobile Outlook by selecting Account - Settings in the upper left corner, then close the mobile Outlook and enter it again and change the language to English, so as to confirm whether it is normal or not.
Clear the cache within Edge on your cell phone:
If you are using Edge browser on your phone, turn on and click on the account icon on the top left corner, click on Logout and turn off synchronization, and then confirm whether it is normal or not after finishing.
Remove and reinstall Outlook:
You can remove Outlook program in your phone, and then re-download and reinstall it through Google Store latter Microsoft official website, after finishing, confirm whether the language is restored or not.
Feel free to text back if you need further help.
If that still doesn't fix it, I suggest you go through Outlook on your phone, click on Accounts in the upper left corner, and then click on “?” in the lower left corner. “ icon in the lower left corner to go to Help & Feedback, and then click on Contact Outlook Mobile Support Staff Program to contact the mobile Outlook team and have them intervene.
Best wishes
Chris.S-MSFT | Microsoft Community Support Specialist