Masato Hagiwara

A wave of gruesome murders is sweeping Tokyo. The only connection is a bloody X carved into the neck of each of the victims. In each case, the murderer is found near the victim and remembers nothing of the crime. Detective Takabe and psychologist Sakuma are called in to figure out the connection, but their investigation goes nowhere...

In a post-war alternative timeline, Japan is divided into the North, controlled by the Union, and the South, controlled by the United States. A mysterious high tower rises within the borders of the Union. Three high school students promise to cross the border with a self-built airplane and unravel the secret of the tower.

Ryuga Dogai faces a new challenge when confronted by another warrior in strange steel armor.