Yui decides to live her life to the fullest, but she can't do that as a blood bank so escapes the Sakamaki manor. However, she gets chased by the Sakamaki's and gets suck in a manhole, luckily she is saved by a mysterious boy who displays more humane characteristics than the Sakamaki's. Unknown to Yui her hero has secrets of his own, what happens when the bros come to reclaim Yui?