There are two kinds of credentials. One is a governmental certificate and the other is a private qualification. You may be able to easily understand the latter. As in other countries, Oracle provides the Japanese version of Oracle Certified Master credentials for those who passed examinations and fulfilled other requirements. (I personally passed the tests necessary for ORACLE MASTER Gold Oracle Database, equivalent to Oracle Certified Professional (OCP), but I have not yet finished the seminar required.) Some other private credentials popular in Japan are Cisco Certification, Microsoft Certification Program, and PMP.
The former may not be well known in countries other than Japan. In Japan, there is an Act on Facilitation of Information Processing where the Ministry of Economy, Trade and Industry certifies people with a certain level of information technology skill. Japan Information-Technology Engineers Examination Center (JITEC) in IPA (Information-technology Promotion Agency) administers the examinations called Japan Information Technology Engineers Examination (JITEE). JITEE is very popular and well known in the Japanese information technology industry. According to JITEC, as of Spring 2010, the examination had been taken by over 15.40 million applicants but less than two million passed successfully.
JITEE has four different levels of examinations.
The lowest level is "Information Technology Passport Examination" to assess the minimum IT skill as a business person. You can take it as a web based test.
The second lowest level is "Fundamental Information Technology Engineer Examination" This is to test the basic skills for IT engineers. This is assessed with paper exams.
The second highest level is "Applied Information Technology Engineer Examination." This is to test the skills necessary for the intermediate level IT engineers.
The highest level has many categories of examinations such as Information Technology Strategist Examination, Project Manager Examination, and Information Security Specialist Examinations. As it is difficult to use only one set of examinations to assess the advanced level knowledge and skills, the examinations are separated into categories such as CIOs (Information Technology Strategist Examination), project managers (Project Manager Examination), and security specialists (Information Security Specialist Examinations). Some of the examinations require an essay, others require writing down the analysis based on a hypothetical situation. (I personally passed several of the JITEEs including Information Technology Strategist Examination which required an essay based on my experience and knowledge.)
Every year, an IT magazine publishes a very popular article on which credentials are necessary and which are not ("Iru Shikaku, Iranai Shikaku"). According to the 2012 version, the most popular JITEE is the Project Manager Examination and the most popular private qualifications are Oracle's Credentials and PMP.