Jitsuroku! Shinwakai  

Authentic Gathering of Gods, 実録！ 神輪会

The story you're referring to is called "A Small Four-Part Saga" by Kurumada. It was written early in his career and showcases many unique aspects of his writing style, including humor, satire, and self-deprecation. One notable example of this can be seen in "Ring ni Kakero," where he parodies both his own work and that of other authors.