Good news, I got my 3rd degree black belt in Hakkoryu jujutsu last night. I think some of my contemporaries in Australia are wondering how I have been able to climb the ladder so quickly. I will take this opportunity to explain the grading system as it is quite different from most contemporary martial arts.
There are only four black belts grades, and no coloured belts or kyu grades in Hakkoryu. The only exception is the Soke sensei (grandmaster), who holds a fifth dan. After obtaining your fourth dan, it is possible to test for shihan (master) status. There are three levels of shihan, and all wear a purple, not black, belt. Purple is the colour of the emperor, and although the connections are not clear to me, Hakkoryu jujutsu and its counterpart Koho Shiatsu have connections to Japanese royalty.
Each grade has its own syllabus of approximately 20 techniques, and the grading system ensures that Hakkoryu practitioners learn these in the optimal order. Each technique represents a principle rather than just a single movement and therefore has infinite variations. Regardless of whether it takes weeks or years, once a student has `mastered` the entire syllabus and can demonstrate an ability to apply the principles within the technique they are ready to grade.
One shihan at the honbu (headquarters) obtained got his purple belt in half a year, but it usually takes several years, especially for students not training at the honbu. That shihan had a long history of training in Aikido, which fast-tracked his progress. I am hoping that my own martial art background will enable me to achieve the same goal within one year. This would give me at least a further six months of training in the shihan levels before returning to Australia. As mentioned below, important teachings are only revealed to shihan.