Japanese Version
The app does not support changing the language to anything other than Japanese.

Non-Japanese Version
The language can be changed by pressing the 'Language Switch' button on the 'Option' screen.
Note: Pressing the 'Language Switch' button will return to the Title screen first, and then the necessary data will begin downloading. Please be aware of this in advance.

Additionally, language changes within the app may generate significant data traffic, so performing this operation under a Wi-Fi environment is suggested.