This is one of the Artist's Proofs sold by Stan directly to his fans at conventions.
"This is number 18AP of 500 copies of the hardcover edition ... each of which has been individually signed, numbered, and illustrated by Stan Sakai." It has a bound-in limitation page with a 4 inch square where Stan has drawn a full scene with Usagi and a dragonfly with mountains and clouds in the distance.
Volume 10 collects issues 1-6 of the Dark Horse comic book series Usagi Yojimbo Volume Three, and stories from issues 13, 15 and 16 of Mirage's Usagi Yojimbo Volume Two, and plus a cover gallery. Introduction by Kurt Busiek.
From the publisher:
Join Usagi Yojimbo in his hare-raising adventures of life and death. Watch as he faces assassins, medicine peddlers, bat ninjas and more! This is a story of honor and adventure. It's a masterful adaptation of samurai legend to sequential art. Dark Horse is proud to present this epic story of good versus evil. Sakai's unique blend of storytelling and Japanese legend has made a unique niche for itself. If you enjoy stories of high adventure and high honor, you will thrill at the saga of Usagi Yojimbo.