From Suse's Bugzilla #37113 by mfabian@suse.de

  remove Kana to improve the appearance of
  Japanese during the installation.
  Kana without Kanji are completely useless.
  They can only cause problems because it can happen
  that they are combined with Kanji from a completely different
  font which looks very ugly. This happens easily in Qt
  applications because Qt unfortunately treats "Hiragana",
  "Katakana", and "Han" as 3 different Unicode regions and may
  select a different font for each of these regions. I.e. if
  FreeSans is set as the main font in Qt while using Japanese,
  FreeSans will be used no only for Latin but also for Kana and
  only for the Kanji a "real" Japanese font like "Kochi Gothic"
  will be used. This looks very bad. If FreeSans doesn't have
  Kana at all, the "real" Japanese font will be used for the
  Kana and the Kanji, which looks much nicer.