76 messages of 1449 are not translated to ja, but exist in en:
* tog-nolangconversion
* january-gen
* february-gen
* march-gen
* april-gen
* may-gen
* june-gen
* july-gen
* august-gen
* september-gen
* october-gen
* november-gen
* december-gen
* faq
* ok
* pagetitle
* feedlinks
* sqlhidden
* blocked-mailpassword
* throttled-mailpassword
* image_sample
* revdelete-nooldid-text
* newpageletter
* boteditletter
* sectionlink
* upload-proto-error
* upload-proto-error-text
* upload-file-error
* upload-file-error-text
* upload-misc-error
* upload-misc-error-text
* upload-curl-error6
* upload-curl-error6-text
* upload-curl-error28
* upload-curl-error28-text
* statistics-mostpopular
* deadendpagestext
* data
* isbn
* allpagesbadtitle
* enotif_mailer
* undeleterevision-missing
* proxyblocker
* sorbs
* rightsnone
* accesskey-search
* accesskey-minoredit
* accesskey-save
* accesskey-preview
* accesskey-compareselectedversions
* accesskey-watch
* category-media-count
* Common.js
* metadata-fields
* exif-fnumber-format
* exif-focallength-format
* exif-photometricinterpretation-2
* exif-photometricinterpretation-6
* exif-xyresolution-i
* exif-xyresolution-c
* exif-colorspace-1
* exif-componentsconfiguration-1
* exif-componentsconfiguration-2
* exif-componentsconfiguration-3
* exif-componentsconfiguration-4
* exif-componentsconfiguration-5
* exif-componentsconfiguration-6
* exif-lightsource-20
* exif-lightsource-21
* exif-lightsource-22
* exif-lightsource-23
* confirmemail_subject
* unit-pixel
* displaytitle
* imgmultigo
* imgmultigotopre

5 messages of 1378 in ja don't use some variables while en uses them:
* pagecategories
* userstatstext
* linkshere
* nolinkshere
* confirmemail_sendfailed