Problems inputting Japanese text
Unfortunately the toolkit Anki uses doesn't handle inputting Japanese text well. This can cause the cursor to appear in front of a word you start typing, or to disappear completely. You can minimize the problems by making sure to always hit the enter key after typing text or converting it to kanji, and ensuring you don't switch fields while the text is still underlined.
Hopefully this behaviour will be improved in a future release of the toolkit.