Statistics of level 1 packages for Japanese in unstable:
Read http://d-i.debian.org/l10n-stats

Outdated:

Translated:
  zipl-installer/*/debian/po/ja.po 1t [ Kenshi Muto]
  s390-netdevice/*/debian/po/ja.po 29t [ Kenshi Muto]
  s390-dasd/*/debian/po/ja.po 16t [ Kenshi Muto]
  pkgsel/*/debian/po/ja.po 12t [ Kenshi Muto]
  partman-xfs/*/debian/po/ja.po 2t [ Kenshi Muto]
  partman-target/*/debian/po/ja.po 25t [ Kenshi Muto]
  partman-prep/*/debian/po/ja.po 5t [ Kenshi Muto]
  partman-partitioning/*/debian/po/ja.po 60t [ Kenshi Muto]
  partman-md/*/debian/po/ja.po 58t [ Kenshi Muto]
  partman-lvm/*/debian/po/ja.po 112t [ Kenshi Muto]
  partman-jfs/*/debian/po/ja.po 8t [ Kenshi Muto]
  partman-ext3/*/debian/po/ja.po 14t [ Kenshi Muto]
  partman-efi/*/debian/po/ja.po 11t [ Kenshi Muto]
  partman-crypto/*/debian/po/ja.po 98t [ Kenshi Muto]
  partman-basicmethods/*/debian/po/ja.po 13t [ Kenshi Muto]
  partman-basicfilesystems/*/debian/po/ja.po 84t [ Kenshi Muto]
  partman-base/*/debian/po/ja.po 68t [ Kenshi Muto]
  partman-auto-lvm/*/debian/po/ja.po 30t [ Kenshi Muto]
  partman-auto/*/debian/po/ja.po 24t [ Kenshi Muto]
  nobootloader/*/debian/po/ja.po 15t [ Kenshi Muto]
  network-console/*/debian/po/ja.po 24t [ Kenshi Muto]
  netcfg/*/debian/po/ja.po 123t [ Kenshi Muto]
  net-retriever/*/debian/po/ja.po 6t [ Kenshi Muto]
  mdcfg/*/debian/po/ja.po 43t [ Kenshi Muto]
  main-menu/*/debian/po/ja.po 6t [ Kenshi Muto]
  lvmcfg/*/debian/po/ja.po 80t [ Kenshi Muto]
  localechooser/*/debian/po/ja.po 45t [ Kenshi Muto]
  lilo-installer/*/debian/po/ja.po 27t [ Kenshi Muto]
  kbd-chooser/*/debian/po/ja.po 14t [ Kenshi Muto]
  iso-scan/*/debian/po/ja.po 31t [ Kenshi Muto]
  hw-detect/*/debian/po/ja.po 43t [ Kenshi Muto]
  grub-installer/*/debian/po/ja.po 57t [ Kenshi Muto]
  finish-install/*/debian/po/ja.po 9t [ Kenshi Muto]
  elilo-installer/*/debian/po/ja.po 11t [ Kenshi Muto]
  debian-installer-utils/*/debian/po/ja.po 14t [ Kenshi Muto]
  clock-setup/*/debian/po/ja.po 15t [ Kenshi Muto]
  choose-mirror/*/debian/po/ja.po 40t [ Kenshi Muto]
  cdrom-retriever/*/debian/po/ja.po 3t [ Kenshi Muto]
  cdrom-detect/*/debian/po/ja.po 28t [ Kenshi Muto]
  cdrom-checker/*/debian/po/ja.po 20t [ Kenshi Muto]
  base-installer/*/debian/po/ja.po 94t [ Kenshi Muto]
  arcboot-installer/*/debian/po/ja.po 11t [ Kenshi Muto]
  anna/*/debian/po/ja.po 12t [ Kenshi Muto]

Missing files:
  aboot-installer/*/debian/po/ja.po 0u
  colo-installer/*/debian/po/ja.po 0u
  floppy-retriever/*/debian/po/ja.po 0u
  mountfloppy/*/debian/po/ja.po 0u
  partconf/*/debian/po/ja.po 0u
  partitioner/*/debian/po/ja.po 0u
  partman-newworld/*/debian/po/ja.po 0u
  partman-palo/*/debian/po/ja.po 0u
  partman-reiserfs/*/debian/po/ja.po 0u
  prep-installer/*/debian/po/ja.po 0u
  quik-installer/*/debian/po/ja.po 0u
  yaboot-installer/*/debian/po/ja.po 0u


Global statistics: 1441t0f0u (100%)     (total strings: 1441=100%)
(From all ja.po files)