This card came as an official, JP-98872, and was waiting for me the day I returned from my Asia trip this spring. I had bought this exact card in Japan and sent it to someone as an official from there a week earlier...
Himeji Castle in Himeji, Hyogo Prefecture, is a UNESCO world heritage site. It is sometimes referred to as the "White Egret Castle" or "White Heron Castle," and you can see why. It is considered the finest remaining example of 17th century Japanese castle construction and is the most-visited castle in Japan.
First built in 1346, Himeji Castle housed and protected various daimyo (regional rulers of feudal Japan) for the next 500 years. After the Meiji Restoration in 1867, the new Japanese government sent the Okayama army to shell the castle with blank cartridges and drive its occupiers out. It was then sold at auction for the whopping price of 23 yen (approximately US$1100 in today's money).
Himeji Castle's architecture incorporates many defense techniques, including loopholes for archers to fire through, angled chutes for dropping stones or boiling oil on attackers, and a confusing maze of paths towards the main keep, so that any attacking force could be watched and fired on for its entire journey inwards. While the castle was never attacked in this manner and thus the system was never really field-tested, even today with the route clearly marked, many visitors have trouble navigating the castle complex. (According to wikipedia.)
The stamp shows a scene from The Tale of Genji, the world's first novel, written by a Heian Period noblewoman.