Etiology of Mirror Writing in Japanese

We read with great interest the review concerning mirror writing by Schott and Schott,¹ in which they commented on a particularly high incidence of left-handed mirror writing among Japanese, whose native language is traditionally written in a leftward direction. In contrast with Hebrew script, Japanese script (both Kanji and Kana) is traditionally written and read vertically, although the lines are read from right to left. This does not mean Japanese languages are written in a leftward direction. Japanese horizontal scripts are written from left to right, the same as alphabetic languages.