She has blue hair which she wears parted on the left , and still has a full horn , which grants her magical power .
One of the twin demons who work at Roswaal 's mansion as maids , Rem is Ram 's younger sister .
sister has blue hair which sister wears parted on the left , and still has a full horn , which grants sister 's magical power .
One of the twin demons who work at Roswaal 's mansion as maids , Rem is Ram 's younger sister .