The Black Goat's Egg

The Black Goat's Egg is the seventh work of Sen Takatsuki.

Summary
The story centers around the relationship between a young man and his mother, a brutal serial killer known as the "Black Goat". Though he is disgusted by his mother's cruel actions, he begins to discover the same depraved impulses exist within him as well. It focuses on graphic descriptions of violence, as well as an exploration of the protagonist's mental state.

Role in the Series
The novel plays a key role in Ken Kaneki asking Rize Kamishiro on a date, after noticing that they were both reading it. This fateful event leads to the Steel Beam Incident, and Kaneki's transformation into an One-Eyed Ghoul. Afterwards, he compares his situation to that of the novel's protagonist, with Rize as the titular "Goat" of the story.

After it is revealed that Ken Kaneki's mother abused him, the parallel further extends to their relationship as well. Though a victim of her violence and neglect, Kaneki struggles throughout the series with the same violent impulses.