Vampire Miyu is based off of a manga series by Narumi Kakinouchi. It first became short four part OVA series in 1988. While generally true to the manga, it was a particularly dark series. In the 90's, another series was produced that was separate from the OAV. It follows a more typical adventure by Miyu. Overall it was more upbeat and more like a magical girl anime.
There in fact is no such thing as a Shinma. The word itself was made up by Kakinouchi, so no there aren't Shinma in legends, although some are based off of folklore. The word Shinma consists of two Japanese characters (kanji): Kami - meaning a god, and Ma - meaning a devil. Japanese Kanji can have a variety of pronunciations depending upon the word, or how various kanji are grouped with other kanji. The kanji for kami is pronounced "shin".
The word itself gives definition to what a Shinma is - a being which is both god, and demon. Shinma are grouped together in clans. In the OAV they point out that Larva's clan is a renegade clan, in the manga there is clarified to be a difference between Western and Japanese Shinma (Larva being from the western sect). The Japanese Shinma lay in slumber, probably for the rest of eternity. It is Miyu's task to return the Shinma who do not sleep to the darkness. This also means that eventually Larva will have to be returned to the darkness as well.
Um... yes and no. The word for vampire in Japanese is "kyuuketsuki" consisting of three kanji, which directly translates into sucking-blood-spirit. If I'm not mistaken this word came directly from China. However if you look at the title, the third kanji has been changed by Kakinouchi to be princess, so the new word is sucking-blood-princess (pronounced "Kyuuketsuhime"?). This is a nice little play on words that the Japanese occasionally like to do, but unfortunately gives translators nightmares. AnimEigo decided to keep the translation for princess when the released the OAV. The manga however was still translated just to Vampire Miyu.
Vampire Yui is sort of a spin off series of Vampire Miyu The third kanji is also changed for Vampire "Princess" Yui, but I'm not getting into that again. Yui's father is a Shinma, and her mother has heritage from Shinma, and blood from Miyu, so it's all sort of tied in there. The story of Yui is totally set apart from that of Miyu, although she does make an appearance in Shin Vampire Miyu.
Character Japanese Voice English Voice ------------- ------------------ ----------------- Miyu Watanabe Naoko Pamela Weidner Se Himiko Koyama Mami Stephanie Griffin Narrator Naya Goroo David Stokes Ryooko Kobayashi Kiyoko Connie Nelson Miyahito Toriumi Katsumi Shaun O'Rourke Aiko's Father Nakamura Hidetoshi Turner Knox Aiko's Mother Matsuoka Yooko Hope Brownewell Doctor Genda Tetsuyoo Lee Dominick Ranka Shoo Mayumi Belinda Bizic Yuzuki Kei Horikawa Ryoo Michael Granberry Shiba Ueda Toshiya Tom Maddis Kei's Mother Asai Toshiko Ellen Lee Kei's Brother Kubota Masato Robert Wailes Kayo Shinohara Emi Linda Carlisle Larva Shiozawa Kaneto Zach Hanner Lemures Mitsuya Yuuji Chad Carlberg Miyu's Mother Ikeda Masako Melissa Stanley Miyu's Father Suzuki Kiyonobu Bob Sayer Akiko Takada Yumi Jessica Watson ----- Vampire Miyu TV ---------------------------------- Miyu Miki Nagasawa Larva Shinichirou Miki Chisato Asao Shirakura Yukari Chiharu Tuzuka Hisae Kokoro Shindou Shiina Mika Kanai