In order to protect Eu from a nemesis known as the ''King of the Night'', the housemates promise to do whatever it takes to keep the quiet necromancer safe.. just as if they were an actual warm (or in Ayumu''s case, cold) and loving family. But unexpectedly, the resident vampire ninja, Sera, has the worst possible orders handed down to her from on high at a critical time like this! Talk about bad timing! Will Sera follow the orders given to her by her clan at the expense of the makeshift little family she and her friends have become?