Rin Okumura and (y/n) (l/n) are now engaged after the horrific events they'd suffered together. Now, they have more to deal with than just demons and Satan. The Vatican decides to get involved, hunting the son of Satan. Not only that, but something else is at work, something more than the Vatican or Rin can handle. This creature makes the skies turn crimson, the waters cloud with the blood of the innocent. Everyone is in danger. According to a mythical prophecy, someone shall die in the process of saving them all...

(Y/n) (L/n), a girl who has suffered from a past of nothing but tragedy and little hope for a brighter future, followed a dear friend to a school held for certain students who keep the country of Japan safe from an unseen foe. Demons. But little does she know that as she attends the cram school of the famous True Cross Academy, she is in the presence of a demon who withholds the flames of Satan within. A klutz who can't stay awake for one whole class period or get over a 50% on a test. Little does young (y/n) know that she would soon be tethered to Rin Okumura, the son of the Devil himself.