The protagonist Ken Kaneki is celebrated for his profound journey of growth and evolution throughout the Tokyo Ghoul story. His transformation is so complex that his character development, especially leading up to the Final Act of Tokyo Ghoul: re, can be mapped onto the five stages of grief: denial, anger, bargaining, depression, and acceptance.

One of the most foundational, yet often overlooked, stages is the original Kaneki Ken (sometimes referred to as "Kon Nei"), who serves as the perfect representation of denial. In this initial state, Kaneki’s denial is rooted in a fundamental lack of resolve—he was unable to let go of something to protect another. The character is forced to confront the harsh truth that his decision-making eventually caused those around him to "perish".

The pivotal transition occurs when he moves from denial to anger. This shift is a moment of resolve, where he makes a solemn vow to eliminate anyone who threatens the people he loves.

This transformation is powerfully represented in the iconic scene where he begins to "eat the false image of Rize". This act is not simply a dramatic moment; it is a profound symbolic declaration. By devouring the image, Kaneki identifies himself as a ghoul and a ghoul only. He not only accepts the ghoul within him but declares that he will surpass Rize and learn how to control his unique power, the Kagune. This step out of denial, fueled by anger and a new resolve, is what cements his status as a complex and compelling protagonist.

This deep character focus on internal struggle also highlights the original series' main theme: psychological horror. However, the later story, Tokyo Ghoul: re, successfully shifts its narrative scope to a larger conflict, detailing aspects like the corruption of the CCG, a difficult narrative change that nevertheless maintained a massive audience. Kaneki's core journey remains the psychological anchor for the entire expanding plot.