Hi Izuru Tokoro no Tenshi (King's Son from the Land of the Rising Sun) by Yamagishi Ryouko is one of the all-time great shounen ai manga. Released first in the early 80's, it's the story of a real historical personage, Shoutoku Taishi, who lived 574-622 AD, at the period when Buddhism was first gaining ground in Japan and the country had not yet settled on a unified political system. Shoutoku Taishi is his posthumous name, by the way. In life he was Prince Umayado, a consummate statesman who ended the period of semi-autonomous clan rule in Japan and united the country under a central government headed by the emperor. (The Emperor in his day, incidentally, was a woman, Umayado's aunt.) The picture on the right, by Yamagishi, is the common conception of him. He was much revered from Meiji times onwards and his portrait was on the thousand yen note until just recently.
But that's the historical Umayado. Yamagishi's Umayado is something else again. Drop dead gorgeous, for a start. An unwilling psychic and mystic, possibly the avatar of a god, and able to think rings around any adult in his vicinity, to continue. And finally, utterly amoral, a cold-eyed politician from his childhood, with a penchant for disguising himself as a woman when needed, batting his long eyelashes at various men when needed, and offing his political and religious rivals.
But Umayado has his Achilles' heel. It's Emishi, the decent and rather dull eldest son of a powerful and nouveau riche aristocratic family, the Sogas. (That's him in the group portrait below, with girlfriend and sister.) Emishi is somehow necessary for Umayado's well-being, and Umayado first fights the attraction and then pursues it, suffering beautifully as a shounen ai hero ought to, even while being beautifully villainous all over the map.
No wonder the series is a classic. History, religious struggles, political struggles, a long ago and weird-even-by-Japanese-standards society, love, hate, obsession, desperation, and a truly mind-twisting take on one of the saints of Japanese history. Do a google search on the title in Japanese and you'll find everything from "I loved it in middle-school and I still do but now that I'm a mother myself it all looks different" to the present day 16-year-old saying "I'm absolutely hooked on Hi Izuru."
The series first ran in Hana to Yume comics and is now available in bunko form, with the addition of a side story Yamagishi wrote about Umayado's children and Emishi's. (Note for the record, that the historical Emishi murdered the historical Umayado's kids. He's considered a serious Badnasty in history, up there with Oda Nobunaga.) There's a Chinese version somewhere, if you can find it. It hasn't been translated into English, won't be translated into English and I rather think can't be translated into English. Which is a very great pity.
Here however are selections from the two collections that Yamagishi released as small posters, showing Umayado in various costumes, some definitely Chinese and some not. The clothing styles of the time were quite distinctive, with trousers worn under robes, quite different from traditional Japanese kimono. I don't know if Japanese clothing in the 6th century was influenced by Chinese styles of the period, or if they predated the great classical borrowing from China that Japan did in the next centuries. Whichever, they sure are pretty.
(Note for people with slower modems: these illustrations are large and may take time to download.)