Shakugan no Shana (灼眼のシャナ, Shakugan no Shana? lit. Shana of the Burning Eyes), also known simply as Shana, is a series of Japanese light novels and related media works written by Japanese novelist Yashichiro Takahashi and illustrated by Noizi Ito centering around Yuji Sakai, an ordinary Japanese high school boy who inadvertently becomes involved in a perpetual war between forces of balance and imbalance in existence. In the process, he befriends the title character: a fighter for the balancing force, whom he takes to calling "Shana". The series incorporates science fiction, fantasy, and slice-of-life "school days" elements into its tale.

Shakugan no Shana Wiki[en.wikipedia.org]
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