Ghost of W

The "Ghost of W", known also as just "The Ghost", was the name given to the anonymous mastermind behind the events that occurred on board the Idinaloq. This included it's sinking, the attempted murder of Merja Amabishi, and the hunt for the keycards played by Hitomi Akeneno, Chisono Shio, and Misaki Himekiri to save Merja's life.

In reality the "Ghost of W" refers to two people, the 'real' ghost who was the actual mastermind behind the Idinaloq incidents, and their accomplice. These two were the "Ghost of Wistarock", the mastermind, and the "Ghost of Wataru", the accomplice and eventual scapegoat, the identities of which belonged to Ritsu Kamiji and Misaki Himekiri, respectively.