Zenitsu is a young man of average height with fair skin and worried-looking eyes that slope downward, transitioning in color from soft brown to gold. His forked eyebrows fade into a warm orange hue. He has short, yellow hair of varying lengths, cut squarely at the ends and fading to a darker orange. His hair loosely resembles a bowl cut and falls unevenly in front of his face. Originally, Zenitsu’s hair was black, but it turned its current color after he was struck by lightning during his training.

Following the battle at Mount Natagumo, his limbs temporarily shrank due to Son’s poison but later returned to normal with the help of medicine developed by Shinobu Kocho.

Zenitsu’s attire consists of a paler brown version of the standard Demon Slayer uniform: a dark brown button-up jacket, a white belt, and tattsuke hakama pants. Over this, he wears his signature haori, which features a yellow-to-orange gradient with a white triangle pattern. He also sports a pair of Kyahan, tied at the front with three white bows matching his haori’s design, along with pale brown tabi socks and white-laced zōri.

Zenitsu is often portrayed as cowardly, anxious, and weak-willed. He frequently expresses a nihilistic outlook, convinced that he doesn’t have long to live due to the dangers of being a Demon Slayer. Despite possessing notable talent and strength, he suffers from low self-esteem, often doubting his own abilities. This is evident when he refused to believe that he had slain a demon, instead crediting Shoichi, a young child with no combat skills, for the feat. Zenitsu lives in a near-constant state of fear, regularly attempting to flee from danger and expressing a desire for a modest, normal life rather than that of a Demon Slayer. His fearfulness leads to frequent shouting and screaming, much to the annoyance of those around him. He also exhibits pessimism, as seen during the Hashira Training, where he criticized Tanjiro and Inosuke for their positive attitudes toward the training.

Despite these flaws, Zenitsu aspires to meet the expectations others have of him and strives to do his best when the situation demands it. He deeply respects his comrades and his late teacher, Jigoro Kuwajima, drawing strength from his inner focus and desire to avenge him. Although he is often self-critical of his cowardice and perceived incompetence, Zenitsu genuinely seeks to improve himself.

Zenitsu exhibits a flirtatious and womanizing behavior, driven by his fear of dying alone. He often hits on girls he finds attractive and asks them to marry him, much to their annoyance. This side of his personality can override his usual timid and quiet demeanor, especially when he believes his friends are “flirting” with girls. In such moments, he becomes hysterical, ranting and complaining for extended periods. Zenitsu also shows a strong attraction to Nezuko, openly expressing his affection and instinctively rushing to protect her. During these times, he can become physically aggressive, lashing out in frustration. Despite his shallow behavior, Zenitsu displays respect for women, as seen when he confronted Daki for harming a girl, demanding an apology without fear, even in front of the enraged Upper Rank demon.

Although he is often cowardly and desperate for attention, Zenitsu has moments of level-headedness, especially when dealing with the antics of his comrades. He frequently becomes annoyed with Tanjiro’s kindness, Inosuke’s boisterous nature, Kyojuro’s loud enthusiasm, and Tengen’s self-promotion, often squabbling with Inosuke over his loud demands. Being the only one of the group to have grown up in a city, Zenitsu is the most street-smart and familiar with Japan’s urbanization, leading to frustration with his partners’ lack of understanding, such as their inability to recognize a train.

Before the raid on the Infinity Castle, Zenitsu adopts a more serious demeanor, appearing focused and determined. He dismisses Tanjiro’s concerns, stating he has something important to handle alone. This shift occurs after receiving a letter from Chuntaro, revealing his master’s death and Kaigaku’s involvement. During his fight with Kaigaku, Zenitsu displays a stern and enraged side, angrily confronting him for disrespecting their cultivator. His sudden change surprises his former senior, showcasing a more mature persona compared to his usual cowardice.

• Indomitable Will:

  Despite his initial cowardice and reluctance to fight, Zenitsu exhibits an indomitable will and spirit. This is first seen when he refuses to let Inosuke harm the demon inside Tanjiro’s box, protecting it to the end even while being relentlessly beaten by Inosuke. During his battle with Daki, while asleep, Zenitsu demonstrated the willpower to continue fighting despite sustaining multiple slash wounds and having his feet broken.

  His sheer determination and anger enabled him to overcome his cowardice and stay awake during later battles against demons, such as his confrontations with Kaigaku and Muzan. In his fight against Muzan, Zenitsu displayed remarkable perseverance, refusing to give up despite being exhausted and injured.

• Tactical Intellect:

  Even when unconscious, Zenitsu exhibits remarkable judgment and tactical intelligence in combat. When fighting consciously, this ability is fully unleashed. This was most evident during his battle with Upper Rank Six, Daki, where he corrected Inosuke’s mistaken deduction about the demons’ weaknesses, accurately stating that they needed to keep both demons’ heads disconnected to defeat them. During his fight with Kaigaku, Zenitsu demonstrated clear thinking and was able to effectively analyze and respond to Kaigaku’s techniques and demonic abilities.

• Unconscious Combat:

  Zenitsu has a unique ability to fight while asleep, which allows him to access his true strength. When awake, his nerves and fear often paralyze him, preventing him from moving. However, when his life is in danger, his fear becomes so intense that he passes out. In this unconscious state, his nerves no longer hold him back, enabling him to fight with remarkable judgment, precision, and skill. His heightened sense of hearing also plays a crucial role, allowing him to perceive his surroundings, locate enemies, and anticipate their attacks. This ability even allows him to continue fighting after falling victim to Enmu’s spell, which induces deep sleep.

• Enhanced Strength:

  Despite his initial cowardice and reluctance to fight, Zenitsu exhibits an indomitable will and spirit. This is first seen when he refuses to let Inosuke harm the demon inside Tanjiro’s box, protecting it to the end even while being relentlessly beaten by Inosuke. During his battle with Daki, while asleep, Zenitsu demonstrated the willpower to continue fighting despite sustaining multiple slash wounds and having his feet broken.

  His sheer determination and anger enabled him to overcome his cowardice and stay awake during later battles against demons, such as his confrontations with Kaigaku and Muzan. In his fight against Muzan, Zenitsu displayed remarkable perseverance, refusing to give up despite being exhausted and injured.

• Immense Speed & Reflexes:

  Even when unconscious, Zenitsu exhibits remarkable judgment and tactical intelligence in combat. When fighting consciously, this ability is fully unleashed. This was most evident during his battle with Upper Rank Six, Daki, where he corrected Inosuke’s mistaken deduction about the demons’ weaknesses, accurately stating that they needed to keep both demons’ heads disconnected to defeat them. During his fight with Kaigaku, Zenitsu demonstrated clear thinking and was able to effectively analyze and respond to Kaigaku’s techniques and demonic abilities.

• Immense Stamina & Endurance:

  Zenitsu has a unique ability to fight while asleep, which allows him to access his true strength. When awake, his nerves and fear often paralyze him, preventing him from moving. However, when his life is in danger, his fear becomes so intense that he passes out. In this unconscious state, his nerves no longer hold him back, enabling him to fight with remarkable judgment, precision, and skill. His heightened sense of hearing also plays a crucial role, allowing him to perceive his surroundings, locate enemies, and anticipate their attacks. This ability even allows him to continue fighting after falling victim to Enmu’s spell, which induces deep sleep.

• Enhanced Hearing:

  Zenitsu possesses a heightened sense of hearing, enabling him to detect danger from even the faintest sounds. This ability allows him to decipher complex layers of sound in various environments, such as the brothels and the Infinity Castle. Demonstrating his exceptional sound detection skills, Zenitsu can perfectly replicate any tune on instruments like the shamisen and koto after hearing it just once, despite having no formal musical training. His perfect pitch is a testament to his auditory prowess. Additionally, Zenitsu’s keen hearing allows him to fight while asleep, using sound alone to navigate his surroundings and keep up with the attacks of demons.

• Extrasensory Perception:

  Zenitsu’s heightened sense of hearing enables him to perceive sounds beyond the normal range of human perception. He can detect a person’s thoughts, emotions, and even personality by picking up the subtle sounds they produce. Additionally, Zenitsu can distinguish between humans and demons by comparing the sounds they make, allowing him to gauge their strength. For example, he noted that Daki, an Upper Rank demon, emitted a sound far more dreadful than that of regular demons.