Rukia Kuchiki is short and petite, with light skin and striking purple eyes. She has black hair that typically reaches her shoulders, with several strands hanging between her eyes. Byakuya Kuchiki has remarked that she bears a strong resemblance to her late sister, Hisana Kuchiki. As a Shinigami of the Gotei 13, Rukia wears the standard black shihakushō uniform.

Twelve years after Yhwach’s defeat, Rukia wears her long hair in a sideways ponytail.

Originally born into a lower class, Rukia retains her modesty even after being adopted into the noble Kuchiki family. She is graceful and “clean” in her demeanor but remains grounded, choosing to interact with ordinary people. However, her cool and reserved nature often causes her to hide her personal struggles, even from close friends. According to Jūshirō Ukitake, Rukia rarely opens her heart and finds it difficult to make lasting friendships.

While inhabiting a Gigai in the Human World, Rukia frequently struggles to find clothes that fit her, leading her to occasionally “borrow” clothes from Yuzu Kurosaki. She has a fondness for climbing to high places and has a particular obsession with all things rabbit-themed. She becomes sensitive when anyone insults her rabbit obsession, and her drawings—usually of rabbit-like figures—are often misunderstood, much to her dismay.

Rukia’s favorite foods include cucumbers, eggs, and rice dumplings.

Approximately 150 years ago, Rukia and her older sister, Hisana, arrived in Inuzuri, the 78th District of Rukongai, after dying in the Human World. Due to the harsh conditions of Rukongai and Hisana’s inability to care for a child, Hisana abandoned Rukia when she was still a baby. This left Rukia to grow up alone, fending for herself in one of the roughest areas of Rukongai. During her time in Inuzuri, she encountered a group of friends led by Renji Abarai, whom she helped avoid trouble after a water theft. She quickly became their spiritual leader, and the group lived together as a makeshift family. The group included Fujimaru, a responsible and witty figure, Kosaburou, a quiet and hardworking member, and Mameji, the timid, good-natured one who often became the butt of jokes.

Rukia’s first day in the 13th Division was somewhat disheartening. Although she asked her fellow Shinigami to treat her like any other recruit, she overheard gossip about the favoritism granted to nobles. Lieutenant Kaien Shiba, however, soon introduced himself to Rukia and scolded her for being too reserved. Rukia was delighted by Kaien’s direct, supportive attitude and felt more comfortable within the Division. That evening, she reported to Byakuya that her day had gone smoothly and that she had not been assigned a Seated Officer position. Unbeknownst to her, Byakuya had arranged for her to remain unseated to protect her, honoring a promise he had made to Hisana. During this time, Rukia worked closely with Kiyone Kotetsu and assisted her on various missions to the Human World.

In the 13th Division, Rukia developed a close bond with Kaien, who became her mentor and taught her both combat skills and valuable life lessons. He introduced her to the concept of the “heart,” an idea that would shape her worldview. Rukia also admired Miyako Shiba, Kaien’s wife, aspiring to be like her one day. Tragically, when Miyako was killed by a Hollow, Rukia accompanied Kaien and Captain Jūshirō Ukitake to eliminate the creature. Kaien, choosing to face the Hollow alone, was ultimately possessed when the Hollow took over his body after destroying his Zanpakutō. Although Rukia initially obeyed Ukitake’s orders not to intervene, she could not bear to watch Kaien suffer and eventually took action, delivering the fatal blow to her possessed mentor. Kaien, before dying, thanked Rukia for releasing him and apologized for dragging her into the situation. This event left Rukia with deep emotional scars, particularly as she struggled to bring Kaien’s body back to the Shiba family without apologizing due to her overwhelming guilt.

Forty years after her adoption into the Kuchiki Clan, Rukia was assigned to the Human World on a mission to Karakura Town. When Kiyone and Sentarō Kotsubaki informed her of the assignment, Rukia mistakenly thought it was a transfer order. Captain Ukitake clarified that she would be in Karakura Town for one month and reassured her that the mission would be simple. Despite this, Rukia chose not to inform Byakuya, believing the mission was too trivial to warrant his attention. As she departed for her assignment, she unknowingly set the stage for her fateful encounter with Ichigo Kurosaki, which would change her life forever.