The Antelope Books is a series that takes place within the Course Books storyworld. It is related and followes the same rules, and even has a few common characters. For example, Hunter Jusenkyou makes a cameo in the first book, and at the same time, Ryo Sansen appears in one of the Course Books.
Books in the Series
The Antelope Books take place on a world of many islands, which rotates almost straight up on its axis, allowing people to live comfortably on every part of the planet. There is little seasonal variation, though it does snow at the poles in winter. The rest of the planet sees rainy and dry seasons throughout the year. Its population are divided into Ninjas, Pirates, and the industrial 'Utopians' who attempt to conquer both.
Because the surface is almost 90% water, sail is the primary means of travel. It's a sea-faring adventure of epic proportions!
Like the Course Books, the Antelope has an over-arching plot that moves through all three volumes. However, unlike the Course Books, it is a series of three novels, instead of short story collections.
Backstory and Similarities
The Antelope series takes place slightly beyond the known worlds of the Course Books, and in the time of the Course Books is actually part of the Known Worlds. Chronologically, the Antelope series takes place around 200 years earlier.
Ryo's world was first seeded with humans some 8,000 years earlier, by refugees from the Mage Wars (possibly of Rinoin origin), in the mid-to-late First Chaotic Period. This would be the beginning of the slow transition into the Dynastic Period. A story that will be seeing print eventually explains how they fled through an ancient Road in front of the advancing Marcon Alliance.
The Marcons, in turn, play fairly heavily into the history of the Course Books, by epitomizing everything bad about absolute rule.