Nozomu Itoshiki is the central protagonist of the anime Zoku Sayonara Zetsubou-sensei, continuing his role as a high school teacher and the youngest son of the influential Itoshiki family. He is a slender, pale man in his early twenties who typically wears a hakama and kimono when outside his hometown, where he prefers casual Western clothing. A defining trait is his name: when written horizontally, the kanji characters form the word “zetsubou,” meaning despair, a fitting reflection of his personality.

His personality is defined by extreme negativity, paranoia, and pessimism. He habitually declares “I’m in despair!” at the smallest of misfortunes and makes frequent suicide attempts, though these are rarely carried out with genuine intent. This outlook began to develop when he accidentally joined a “Negative” club during his first year of high school. The character is loosely based on the protagonist of Osamu Dazai’s novel No Longer Human, which is both his own and the author’s favorite book. Despite his bleak worldview, Nozomu possesses a dry, sarcastic sense of humor and is highly intellectual, often steering conversations into philosophical and satirical territory. He genuinely cares about his students’ well-being, though his pessimism frequently undermines his teaching and personal relationships.

In the story of Zoku Sayonara Zetsubou-sensei, Nozomu serves as the anchor for the series’ comedic and satirical sketches. Many of his students, especially the girls, develop romantic feelings for him, but these are usually based on misunderstandings of his words. His most notable counterpart is Kafuka Fuura, an relentlessly optimistic student whose perspective directly contrasts with his own. Other key relationships include Chiri Kitsu, a perfectionist class president who insists on marrying him, and various students with extreme traits that fuel his despair. Over the course of the series, Nozomu’s negativity remains consistent, but he occasionally reveals a more vulnerable and caring side, especially when he attempts to guide his students despite his own helplessness.

Due to his numerous brushes with death, Nozomu exists on the border between life and the afterlife, granting him the unusual ability to perceive and interact with the spirits of the deceased. This ability is used sparingly and adds a surreal layer to his already exaggerated character. Overall, Nozomu Itoshiki is a deeply pessimistic but intellectually sharp teacher whose extreme outlook drives the series’ relentless satire of modern Japanese society and human nature.