Sengoku jidai

The was an unstable period of time in Japan from about the 15th century to the 17th century in which political, social and military unrest was common place. It was a time of war and chaos and constitutes the latter part of the "Feudal era" of Japan. The Sengoku period was roughly 500 years before Kagome's time in the modern era.

Explanation of Time Travel
The modern time is "-X-", a period in the Sengoku jidai is "-Y-", and 50 years before -Y- is "-Z-". At -Z-, Kikyō dies soon after sealing Inuyasha to the Goshinboku, causing him to go into suspended animation. She is then cremated with the jewel. 50 years pass and the story takes place at -Y-, where Inuyasha is still in suspended animation. At -X-, Kagome Higurashi, the 20th century reincarnation of Kikyō, is pulled into the Bone-Eater's Well bringing the jewel embedded in her body with her. She ends up at -Y- where she frees Inuyasha and they start their journey together.



Trivia

 * Although the series takes place in the Sengoku period, in the English dub this is often simply translated as the "Feudal era". While this is not wholly inaccurate factually, it is nevertheless an inaccurate translation. The so-called "Feudal era" of Japan is a much broader time period that stretches for many hundreds of years, and only encompasses the Sengoku jidai as its final stage.
 * It is explicitly stated that the Band of Seven were executed prior to the introduction of matchlock rifles in Japan. As matchlock firearms first appeared in Japan in 1543 and the series takes place ten years after the Band of Seven's defeat by the northern warlords, that suggests that the Band of Seven was defeated prior to 1543, and that the series takes place between 1543 and 1553.
 * Although the series suggests that Kagome travels approximately 500 years into the past, this would likely place her in or around the vicinity of the late 15th century, either prior to or at the very start of the Sengoku era. Given that Kagome lives in the late 20th century and that the series can be dated to within 9 years after 1543 (see above), it would be more accurate to say that she travels back in time by a measurement of 400-450 years.