Strait Jacket (ストレイト・ジャケット) is a light novel series by Ichirō Sakaki with illustrations by Yō Fujishiro, published by Fujimi Shobo under their Fujimi Fantasia Bunko imprint. It was published in 11 volumes between 2000 and 2010. The series was adapted into a 3-episode original video animation series in 2007. A film version of the OVA aired in the United States on the Syfy channel.
Plot
Strait Jacket is set an alternate history where magic was proven to exist in the year 1899. The use of sorcery spread throughout all facets of society and changed the social and technological development of the world. The location is Tristan, an urban metropolis that appears to be an amalgamation of turn-of-the-20th-century Tokyo, San Francisco, and Victorian-era London.
Alongside this technology and science exists magic, which has been proven possible in public demonstrations by Dr. George Greco. Although the use of magic is only possible for a few talented individuals, it is very dangerous and highly illegal. Due to an invisible contaminant called the "malediction", or simply the "curse", people who use magic too often are at risk in transforming into "Demons