Yes. You can use the app in English* after following the steps below.
*The only language available other than Japanese is English.
①Tap on "お客さまメニュー(Customer Menu)".
②Scroll down and select "言語(Language)" in the settings section.
③After the language selection screen opens, select "English".
④When the popup "To apply this setting, you have to restart the app" appears, tap the "Exit" button.
⑤Once the app closes automatically, restart it.
⑥The app will now display in English.