If you decide that you no longer want to play Monster Hunter Now and would like to delete your account, then you can check out this guide from Seeking Tech to see how you can properly do so.
1. From the main menu, tap your profile picture on the lower left corner.
2. Next, you need to tap Settings.
3. From the Settings menu, scroll all the way down to the bottom. You should see the Delete Account option with the following description:
Once your Monster Hunter Now account is deleted, it will no longer be accessible by you or anyone else. This action cannot be undone.
Select Delete Account.
4. You should see a pop-up notification with a 10-second countdown.
Once the countdown has been completed, tap the Continue option to start the account deletion process.