Heiji Rei Kim is an unlucky 18 year old boy work as a mail carrier after his parents died in car accident 11 months ago. Heiji Rei Kim suddenly meet 'Hae' Arendelle, a 14 year old Girl Born with Royal Blood and the sole heir of the wealthy Arendelle estate. She hires Heiji as her new Personal Bodyguard ( But Why did he get hired? Let's see ) But aside from performing his ordinary duties as a Personal Bodyguard, Heiji must fight to protect Hae from harm, a difficult task since Her life is always in danger.