NOTE: All the names for menus and the locations might be slightly different depending on the devices.
Open the Play Store and search “Gboard” (There are other keyboard apps such as Swiftkey that offer Japanese input with similar setup processes, but we will just focus on how to set up Gboard in this article).
Install the app and open it, following instructions to lead you to the Language & Input Settings of your device. Toggle the Gboard keyboard on and select your permissions. Then it will redirect you to the settings of the app where you can click on Languages, click Add Keyboard, and search and download Japanese. It will then give you the option to download 12 keys (flick input), QWERTY, handwriting, and/or GODAN. We will simply introduce you to the flick input and the QWERTY input in this guide, but you can also play around with the handwriting and GODAN keyboards if you like!
To toggle between romaji input and kana input on either layout, simply click the lowercase “a” or あ in the bottom left corner of the keyboard.
To switch between flick input, QWERTY, and your English keyboard, click on the globe icon.