Ushio is somewhat shorter than his peers, including his classmates Asako Nakamura and Mayuko Inoue, but possesses a lean and athletic build reflective of his active lifestyle. He has short, spiky black hair and thick eyebrows, features that contribute to his energetic and expressive demeanor. His usual attire consists of a striped shirt with rolled-up sleeves and jeans, though he often changes outfits throughout his travels. At school, he wears the standard male uniform, a black gakuran over a white dress shirt. In the manga, he is occasionally seen wearing Shinji Tokuno’s overcoat.

When wielding the Beast Spear, Ushio undergoes a notable transformation. His hair grows significantly longer, and he is typically seen shirtless in this form. His eyes become more intense, with enlarged pupils and narrower irises, and several of his upper teeth extend into small fangs, reflecting a more feral appearance.

As the influence of the Beast Spear begins to consume him, Ushio’s transformation into an Azafuse begins. His eyes take on the appearance of fractured blue crystals, his facial features become more gaunt and distorted, his eyebrows split and thicken, and fur begins to grow along his scalp. His nose becomes compressed, and all of his teeth transform into sharp fangs, signaling a complete loss of humanity in this state.

Ushio Aotsuki is characterized by his loud, impulsive, and stubborn nature. His brash demeanor often causes friction with classmates and teachers, who view him as disruptive, academically poor, and lacking social tact. He frequently engages in heated arguments and physical confrontations particularly with his father, Shigure, and the youkai Tora often over trivial matters. Ushio also displays a disregard for organization and cleanliness, exemplified by his cluttered school desk, which once contained a spoiled sandwich and a soaked shirt from weeks prior.

Despite his flaws, Ushio possesses a strong moral compass and a fiercely protective nature. He is deeply loyal to his friends and family, often risking his life to protect others, including strangers and former enemies. His altruism and emotional vulnerability are key aspects of his character; he is unafraid to show compassion, even toward those who have wronged him. Ushio’s empathy allows him to influence others, as seen when his tears persuade Juro to reconsider his hatred of humans.

Ushio can be naïve and occasionally makes insensitive remarks without realizing their impact. He remains oblivious to the romantic feelings held by Mayuko, Saya, and Yu, largely due to his emotional immaturity and focus on Asako Nakamura. His upbringing without a maternal figure and adolescent mindset sometimes lead to sexist or dismissive comments, such as underestimating women in combat roles.

Nevertheless, Ushio’s courage, determination, and sense of justice define his character. He persistently seeks to do what is right, regardless of the consequences. His willingness to sacrifice himself for others, coupled with his emotional growth throughout the series, shapes him into a compassionate and heroic figure.

Mastery of the Beast Spear
After unsealing and becoming the wielder of the legendary Beast Spear, Ushio rapidly develops into a highly skilled spearman. He demonstrates remarkable proficiency with the weapon, capable of taking on numerous powerful youkai with agility and precision. Even in his untransformed state, Ushio showcases notable combat versatility and reflexes, frequently relying on the spear both for defense against hostile spirits and to keep Tora in check.

Enhanced Strength, Speed, and Reflexes
When empowered by the Beast Spear, Ushio undergoes a physical transformation that dramatically amplifies his physical capabilities. In this state, he can lift massive boulders with ease and unleash enough force to send a bus flying with a single push. His speed and reflexes increase to superhuman levels, allowing him to keep up with formidable opponents, including Tora, whose flight can produce sonic booms.

Accelerated Healing and Durability
The Beast Spear grants Ushio an enhanced healing factor, enabling him to recover from serious injuries at a rapid rate. This regenerative ability, combined with an increase in physical resilience, allows him to withstand attacks that would be fatal to an ordinary human. Despite sustaining frequent wounds in battle, Ushio consistently returns to the fight thanks to the spear’s restorative properties.

Unarmed Combat Proficiency
Though not formally trained in martial arts, Ushio is a capable hand-to-hand combatant. His raw physicality and instinctive fighting style make him formidable even without the spear, and he often blends unarmed strikes with spear techniques during combat.

Spiritual Connection to the Beast Spear
As the chosen master of the Beast Spear, Ushio can summon it to his hand at will, even from a distance. When he channels its power, his appearance changes dramatically: his hair grows down to his feet, his eyes become sharp and animalistic, and his aura takes on a feral intensity, making him resemble a youkai himself. This transformation is both a visual and spiritual manifestation of the spear’s power merging with his own.

Shigure Aotsuki
Ushio shares a complex yet affectionate relationship with his father, Shigure Aotsuki. Although the two frequently argue and engage in minor scuffles often initiated over trivial matters there is a strong underlying bond between them. Shigure raised Ushio alone following the presumed death of his wife, and his strict parenting style stems from both concern and a desire to protect his son from danger. Despite his disciplinary approach, Shigure is shown to be deeply protective of Ushio, particularly when shielding him from the secrets of their lineage, including the existence of the Beast Spear and the identity of Ushio’s mother. Ushio initially underestimates his father’s strength, but is surprised and impressed upon witnessing Shigure’s power during a confrontation with Tora. Their mutual concern for each other’s safety is evident throughout the series.

Sumako Aotsuki
Throughout his early life, Ushio was told that his mother, Sumako, had passed away. Growing up without her left him feeling isolated and defensive; any mention of his mother would provoke an aggressive response. A turning point occurred when Asako’s father gently reprimanded Ushio, advising him that his mother was always watching over him advice that left a lasting impression. Ushio later learns that his mother is alive and engaged in a lifelong battle against the monstrous Hakumen no Mono. During his journey to find her, Ushio reflects on his longing and loneliness but ultimately chooses not to burden her with those feelings. Instead, he comes to admire her resolve and sacrifices, realizing the weight of her duties and the courage it must have taken to face such an ordeal alone.

Mikado Hizaki
Mikado Hizaki, a distant ancestor of Ushio and a revered figure among the spiritual lineage of the Beast Spear, requests to meet him before the battle with Kuragi. Although initially nervous, Ushio is struck by her resemblance to Mayuko and quickly warms to her kind demeanor. Their brief interaction is marked by a mix of reverence and humor Mikado offers him candy, and despite his initial protest that he is not a child, his growling stomach betrays him, prompting shared laughter. Their exchange reinforces Ushio’s connection to the spiritual heritage of the Beast Spear and the sacrifices of those who came before him.