I tried the Japanese kana input method (prior to that I used romaji method) but it seems designed for Japanese hardware keyboard, which has one more key on the next to the right-shift key.
However on the US-English, there is no such redundant hardware key, making it impossible to type in ろ character.
So is there any way to type in ろ in US-English keyboard on macOS?
Best Answer
Using the Japanese Hiragana Input Source, with the preference for Typing Method set to "Kana", you should find ろ at Shift plus け (the key marked ' on the US keyboard), next to the return key, as shown below:
Keyboard Viewer is useful for solving such problems.