The Gosei title is decided in a best of five match. The challenger is decided in a large knockout tournament starting with about 40 players. The 17th edition will give you an idea of the current tournament structure.
The Gosei tournament formula initially consisted of a knockout preliminaries to qualify for the challenger league. In case of tied 1st place a challenger playoff would decide the challenger of the title holder. The 2nd edition is a good example of this formula.
The formula changed again with the 5th edition. A challenger knockout tournament decides the two players who will compete in a best-of-three match the challenger for the title match.
The Japanese Title Overview page shows what's available.
In the overview players link to their biographies while results link to a detailed description of the edition.
If you have additional information to the supplied info or if you can supply us with the results of other tournaments please send an E-mail about it and it will be included on these pages.