There are in fact two sequels to Bridge of Birds: The Story of the Stone, and Eight Skilled Gentlemen.
They're all available in an omnibus volume from The Stars Our Destination, an SF store/publisher. The original hardcover is long sold out but apparently they just did a trade paperback reprint.
I'm surprised that no one has mentioned the L5R books, Clan Wars and Four Winds. Not thegreatest literature of all time, but heavily influenced by the characters and setting of the ccg and rpg.