Obi has short deep brown hair, striking yellow, cat-like eyes, and a scar above his left eye, which is usually partially concealed beneath his fringe. His physical features, particularly his eyes, give him a sharp and agile look, reflecting his quick reflexes and stealth-based skillset.

In his earlier appearances, Obi dresses in practical and rugged clothing, suited for travel and mobility. His preferred outfit includes a dusty sand-yellow headband wrapped around his head and ears, a khaki-colored shirt, a black long-sleeved undershirt, black pants, gloves, boots, and a neck wrap. As the series progresses, Obi’s attire becomes more refined and formal, particularly during missions that require official representation. Nevertheless, he continues to favor dark colors and functional clothing to aid his nighttime movements and concealment.

When acting in an official capacity as Zen Wistaria’s messenger, Obi typically wears either a black buttoned long-sleeved uniform or a light-colored short-sleeved tunic paired with a black long-sleeved undershirt. When not on duty and casually around the castle, he is often seen wearing the latter outfit with a loose neck warmer, a staple of his look regardless of the occasion.

During his time in Lilias, Obi’s outfit consists of black underclothes, a white tunic, a fur-lined neck warmer, and a shoulder cape that drapes over his right shoulder and arm, combining practicality with a more polished appearance. His clothing choices consistently reflect his adaptability balancing formality, stealth, and readiness for action.

Obi is a reserved and guarded individual who, despite holding Prince Zen Wistaria and Shirayuki in high regard, chooses to keep an emotional distance from them. He rarely speaks about his past and is reluctant to let others become too familiar with his personal history. While he is deeply loyal and protective, particularly toward Zen, Mitsuhide, and Shirayuki, Obi prefers to operate from the shadows, using the skills and instincts he developed from his former occupation to gather information, track threats, and ensure the safety of those he now considers important.

Before meeting Zen and joining his circle, Obi lived a solitary and emotionally detached life, intentionally avoiding relationships or ties that could bind him. He was used to working alone and relied solely on himself. However, after becoming part of Zen’s trusted group, Obi undergoes significant character growth. He begins to rely more on others, learns to trust and support his companions, and finds a renewed sense of purpose in watching them grow and protecting their futures.

Obi is known for his nocturnal habits, often choosing to be alone outside at night, which aligns with his preference for operating in darkness and his ease in moving unnoticed. His methods are frequently unorthodox, such as entering rooms through windows or balconies rather than doors, emphasizing his agility and stealth.

He is a nimble and highly skilled fighter, capable of adapting quickly in combat. Obi can fluidly switch between sword fighting and hand-to-hand combat, and even demonstrates unique acrobatic techniques, such as standing on his hands and using his feet to disarm opponents. He also carries shuriken (throwing stars), reinforcing his experience in stealth-based tactics.

Despite his aloof nature, Obi gradually becomes an irreplaceable presence in Zen’s inner circle, showing unwavering dedication and growing emotional depth as he learns to open up and trust those around him.

Very little is concretely known about Obi’s past before his introduction in the main story. At one point, he jokingly or perhaps truthfully claims to have met Shirayuki during her childhood, potentially in the mountains of Tanbarun, before she went to live with her grandparents. He mentions this in a conversation with Shirayuki and Zen, stating that he had encountered her in Tanbarun, despite never having been to its capital. Whether this statement was sincere or a teasing remark remains ambiguous, but it hints at a past more intertwined with the main characters than initially assumed.

Before becoming Prince Zen Wistaria’s aide, Obi worked in a dangerous and morally gray profession, taking on jobs that were either too risky or undesirable for the average person. He has openly admitted that these jobs were often illegal, with strong implications that some may have involved assassination or mercenary work. His agility, stealth, and unorthodox combat skills reflect this background.

During one particularly high-risk mission, Obi sustained a serious injury, receiving a large wound across his chest. When his comrade, Torou, attempted to check on him afterward, Obi disappeared into the woods, prompting speculation within their former network. Rumors circulated that he had either died or had vanished to start a quiet life, possibly settling down with a family. In truth, this marked the beginning of his departure from that life.

Obi’s final mission in this line of work came when he was hired by Haruka, Zen’s aide and the Chief of Staff of the Royal Palace, to interfere with Shirayuki’s presence in Wistal. Haruka sought to remove her from the palace before she could become too close to Zen. However, through this mission, Obi met both Shirayuki and Zen—an encounter that would change the trajectory of his life. Rather than fulfilling the job, Obi defected and ultimately pledged his loyalty to Zen, finding a new purpose and forging a new identity as part of Zen’s trusted inner circle.

Zen Wistaria
Obi serves as one of Prince Zen Wistaria’s trusted aides and often refers to him as “Master.” Their relationship began on uneasy terms due to the nature of Obi’s original mission, but after proving his skill and loyalty, he was accepted into Zen’s inner circle as an official messenger and Shirayuki’s personal guard. Over time, Obi developed a deep bond with Zen, characterized by a mix of loyalty, respect, and playful teasing.

Obi frequently jokes about Zen’s romantic life, occasionally complimenting Zen’s eyes or suggesting ways to treat Shirayuki better sometimes by setting an example himself, much to Zen’s annoyance. Despite the lighthearted banter, Zen is aware that Obi harbors feelings for Shirayuki, yet he trusts him deeply and is confident that Obi knows where he stands. Obi, for his part, has admitted that he intended to leave one day, but chose to remain because of his growing attachment to Zen.

Their relationship is close enough that Obi can purposefully tease Zen or make him jealous, without inciting true anger. Zen never doubts Obi’s loyalty, and Obi, in return, respects Zen enough to remain steadfast in his duties and never act on his feelings for Shirayuki.

Shirayuki
Obi addresses Shirayuki with respectful nicknames like “Miss” or “Little Miss” (translated as “My Lady” in official versions). His feelings for Shirayuki began to surface after he rescued her from collapse due to exhaustion at Fort Laxdo, and those feelings gradually deepened throughout the series. Despite his affection, Shirayuki remains unaware of his romantic interest.

Obi is extremely attuned to Shirayuki’s emotional and physical state, often sensing when she is overworked or upset. He admires her strength and independence, though her stubbornness sometimes complicates his protective role. Because of his speed, agility, and discretion, Obi is considered the most suitable guardian for her during travel and politically sensitive missions.

When Shirayuki is assigned to Lilias for two years, Zen commands Obi to accompany and protect her as both a knight and messenger. Prior to this, Obi confesses to Zen that he has feelings for her, further solidifying his internal struggle between personal affection and professional duty.

Though their relationship remains platonic, Shirayuki grows close to Obi, confiding in him and showing her appreciation. In one moment, she tells him he looks nice under firelight and admits that she can be herself around him, highlighting the deep trust and comfort between them.

Mitsuhide Rouen
Obi shares a friendly and sometimes teasing relationship with Mitsuhide, another of Zen’s aides. He refers to him as “Mister” and often pokes fun at his serious and sentimental nature. Despite the teasing, Obi holds Mitsuhide in high regard and values him as a reliable comrade who genuinely cares for others. Their camaraderie is marked by mutual trust and cooperation, especially in high-stress situations.

Kiki Seiran
Obi and Kiki maintain a professional and somewhat distant relationship, though they rely on each other readily when duty calls. While they do not often engage in personal conversations, they work efficiently as a team, and Kiki trusts Obi enough to watch over both Zen and Shirayuki in her absence, as seen in Chapter 89.

Earlier in the series, Obi made occasional flirtatious remarks toward Kiki, though they were never serious. These romantic innuendos were more playful than genuine, and Kiki never responded to them in kind. However, Obi was genuinely surprised upon learning about Kiki’s engagement, indicating that while his flirtation was casual, he still held a quiet curiosity and respect for her.