Post Graduate Degree accepted for Work Visa

I have recently completed a Post Graduate Certificate in Business Administration which is ordinarily the equivalent to or greater than a bachelors degree.I do not have a bachelors degree as I went with the work experience entry route at my university.I plan on eventually upgrading to full MBA in the future though.My question is,will the japanese visa bureau accept a Post Graduate Certificate/Post Graduate Diploma/MBA in lieu of a bachelors degree?
What qualification levels mean: England, Wales and Northern Ireland - GOV.UK

I think I've only run across this question once in 20 years. My advice is to get your institution to create a certified statement attesting to the equivalency. Run it by a lawyer, or ask immigration before creating/submitting it.