The text on the Mitaka cube has no vertical alignment, the text is justified on both sides.

PDF version to zoom in the text.
XLSX file with other texts (needs to install the TTF font, see below)

It contains alphabetic padding sequences shown in grey filling. These sequence follow the traditional order of letters, with the exception of syllable "Du" and letter "L". Here is the old Persian syllabary:

Other repeated sequences are found. Fixed typo in green, meaningless characters in red. Ideograms and fullstops in blue filling.

I found no real Japanese, but neither the little old Persian I know. The best candidates are the red sequence at b26: "Maathakaith kudaasai" and the orange at c12: "Tanusikaatta".