Board Thread:Questions and Answers/@comment-16544958-20131218132129/@comment-24420340-20140114014527

In Chapter 208, Kouen says that ten years previous, he was in a position far from that of the succeeding prince, and goes on to list Hakutoku's, Hakuren's, and Hakuyuu's deaths (followed by his own father, though that doesn't really come into play here). Given that, Hakuyuu would be 32, and Hakuren would be 29, placing one just a little younger than Sinbad (but a year older than Kouen), and the other two years older. Of course, the description doesn't explicitly -say- that they died ten years ago, and it could be that Kouen was reflecting on his life from a decade earlier.