In the wake of a long-forgotten pact between ninja clans and underworld forces, an old rivalry stirs once more after centuries of uneasy peace. Young trainee Midou Miko is given her first assignment to protect the human realm from returning supernatural threats. Relying on her family’s legacy of combat skills and arcane arts, she faces the opening skirmish with determination and agility. As the new boss of the underworld begins to assert influence, Miko’s resolve is put to the test in this decisive first episode.