It is a warring period in feudal Japan. The warlord, Nobunaga Oda, is rapidly vanquishing his foes on a quest to pacify and unify the country under his rule. However, there is one domain that he forbids to lay a hand on, that of the Iga ninja, whom even the great Nobunaga fears most. The Iga are known to wield extraordinary and supernatural powers as invincible weapons of war who will assassinate anyone for money, and money only. They don’t think of people as human and are dubbed “the killer clan”. But there is one Iga ninja, Mumon, who while peerless in ability is indolent and taken to task for an inability to earn much of an income. In the fall of the year Tensho 7, Nobunaga’s second son, Nobukatsu Oda, decides to ignore his father’s orders and attack the Iga country, partly encouraged by Taizen Heki, a man who had once turned on his master and was now employed as a vassal of Nobukatsu. Heibe Shimoyama, whose brother had been killed by Mumon also seeks revenge on the 12 Iga ninja core, including Sandayu Momoji and Kai Shimoyama. Amid various colliding interests and schemes, ultimately, a major bloody showdown is coming between Oda’s army and the Iga ninja.

At the Tojo University Hospital, a group of specialists in the type of heart surgery called the “Batista operation,” which is said to have a success rate of 60%, have formed a specialist team called “Team Batista,” and the team is improving their record miraculously with 26 consecutive successful cases. However, all of a sudden, there are three operational death cases in a row. Are they just accidents? Or murders? A doctor, Taguchi is assigned to conduct an internal investigation. Taguchi, who knows nothing about surgery, reluctantly plays the role of a detective, but, not surprisingly, things don’t work. When Taguchi is trying to wrap up her investigation by determining that those operational deaths are simply accidents, a daring and astute government official of the Ministry of Health, Labor and Welfare named Shiratori shows up in front of Taguchi, saying “These are murder cases. The suspect is among the 7 members of Team Batista!” The two investigate the Team Batista members once again…

This time, the scandal is in ER.- A mysterious letter arrives for Dr. Kimiko Taguchi (Yuko Takeuchi), a specialist in “unidentified clinical syndromes” at Tojo University Hospital. The letter reads: “Chief Surgeon Hayami of the Emergency Center has a collusive relationship with a medical supplies maker. And the head nurse is in on it with him.” - Somewhere under all the mystery lies an unimaginable truth.