Interestingly, the Japanese began to adopt Western medical techniques at the same time they were closing the book on a rather disasterous chapter of Western cultural incursion. When guns arrived for the first time in 1543 with Portugese traders, Japan was fifty years into Sengoku Jidai ("Age of the Country at War"). Feudal lords were vying for military control of the country, and so began to purchase large quantities of guns from the Europeans for an upper edge. The lords learned quickly that, with the musket, the greatest warrior with a lifetime of training could be easily killed by a footman with only a minimal set of skills.
For the next 200 years, encroachment of Western culture was literally confined to an artificial island, known as Dejima. Forged from a natural penisula, there was only one bridge on and off the island with a guard on either end to prevent foreigners from interacting with the mainland. At this time in Europe, great strides were being made in medical science. Holland began sending scientists to Dejima, who would bring their various books of learning with them. Some of these books would then be sold illicitly to Japanese scholars or offered as gifts to the shogun. Eventually, an exchange of information between the Dutch scientists and Japanese scholars was formalized in what became known as the Rangaku Movement. Appointed scholars could study and learn European sciences, but could not practice them.
One student in particular, Sugita Genpaku, obtained a copy of Ontleedkundige Tafelen, a Dutch anatomy book, and it blew his mind. The Japanese had never practiced any form of dissection. Making an official inquest to dissect the bodies of executed criminals*, Sugita was amazed by the detail and accuracy of the anatomy illustrations. Eventually, he published the Kaitai Shinsho, Japan's first anatomy book. Beholden to the European aesthetics, the book even sports Greek columns and a Classical style of illustrating anatomy. As Pink Tentacle points out, the typical anatomy illustration of the day featured an idealized physique in Classical Greek pose and a placid expression on the face of person whose organs are yet exposed.
In 1819, Minagaki Yasukazu (南小柿 寧一), a physician from Kyoto, painted these illustrations as part of an ongoing Rangaku correspondence with Dr. Philip von Siebold. 83 illustrations from over 40 dissections, and there's little information available beyond that. But what we can glean from these remarkable illustations is that Minagaki was interested in disseminating accurate anatomical information in an aesthetic style more familiar to the Japanese than the Classical Greek bodies of the Kaitai Shinsho, with their placid expressions and disemboweled organs. Here, the faces of these executed criminals look twisted in anguish and bodily fluids pool beneath body parts. There's a realism to them that the European anatomies of the time lacked -- which is the more macabre is up to the taste of the reader.
* The Japanese weren't the only ones who used the cadavers of executed criminals to learn about the human body. In Europe and America, though it was technically illegal, almost all of our knowledge of human anatomy came from executed criminals or robbed graves. In England, anatomy instructors would even tell their students exactly how many corpses they were required to furnish for their own studies that semester. Universities officially employed grave-robbers to keep up with growing demand in the medical field, and their income was substantial. It wasn't until the twentieth century that grave-robbing ceased to be an unspoken prerequisite in college anatomy classes. In general, the students would pay professional "resurrectionists," who might dig up as many as 500 corpses in a year.
• All 83 illustrations of the Kaibo Zonshinzu used to be hosted online at the Tohoku University Library until very recently. As far as I can tell they are no longer availabe, but I will keep a weather eye to post them here again when I find them.