If you enable 'Automatically switch to the second language' option, you can do : When English is input, it is translated into Japanese, and when Japanese is input, it is translated into English. In the toolbar popup, translate the input text in real time. If you enable 'Do not display the button if translation is not required' option, you will not get frustrated by the button appearing when it is not necessary.
When you select text, the translation button pops up and the translation is displayed instantly.
