There was a peaceful land in the south of the Japanese territory, the Shinju Kingdom lead by a King with his 3 daughters, Eli, Maki and Honoka.
Then a knight came into the side of the oldest daughter, her name was Shirei, a knight with a sword, she was know for scarlet demon because of how she kill her opponents by slashing them in the neck and sometimes her sword will be full of blood in just a few minutes of war.
But when she was trusted to protect Eli, her heart becomes soft, she become more gentle in order to serve the lovely Princess and eventually falling for her and they both become one in terms of heart and soul, they promised that they will never leave eachothers side forever...
But that forever became a mirror broke into pieces when the King knew there secret, he forced the two lovers to let go of eachother starting with the Knight, letting go of her love...