The story is set in a not too distant future, in which Earth has been overrun by a horrifying technovirus. Mechanical parasites, mistakenly created in an attempt to advance technology, attach themselves to human spinal cords and turn their hosts into cyborgs. Desperate to rid themselves of this technological terror, the remaining human survivors try to band together and learn to defend themselves against android enemies.

[From Manga-Mania]:

Reichieru has just moved to Ragnarock City, where she is attending the St. Freyr School. But, will she be able to cover up her special secret while adapting to the fashion of the modern city?