|We Azumabito have always adapted to tumultuous times. But now look what's become of us...derided as wretched, penny-pinching vixens...Still...we have not lost our pride as a clan. The pride your mother handed down to you.|
|— Kiyomi Azumabito to Mikasa|
Before the Great Titan War, the Eldian Empire and the nation of Hizuru were allies. A son from the Shogun clan (that would later become the Azumabito family) had a close relationship with the Fritz family. When King Karl Fritz moved the capital of Eldia to Paradis Island, that son was invited to stay. He began the "Asian clan" inside the Walls.
When King Fritz erased the memories of the Eldians inside the Walls, the Asian clan was unaffected due to not being Subjects of Ymir. After turning against the Royal Government alongside the Ackerman clan and rejecting the King's offer of nobility, the Asian bloodline was exiled from society and hunted down. By the year 844, it was said that the Asians had been hunted down to near extinction within the Walls.
According to Kiyomi, the family changed during the times of great turmoil and stigmatized into a bunch of grubbing scheming foxes for the sake of their investments.
During the Battle of Trost District, Mikasa Ackerman recalls the time from her childhood when her mother and father were killed by robbers who were hoping to sell her and her mother to potential buyers in Mitras. She is rescued by Eren Yeager, killing two of the traffickers before Mikasa kills the third with her awakened Ackerman abilities. After the death of her mother, Mikasa Ackerman becomes the last surviving member of the Asian bloodline known to exist within the Walls.
In a conversation with Levi Ackerman before their confrontation with Kenny Ackerman and his subordinates, Mikasa mentions how her mother's family lost their home, possibly due to their Asian heritage.
Kiyomi Azumabito meets with Zeke Yeager sometime between 850 and 852. He tells her of his wish for the resurgence of Eldia and how helping him would in turn benefit Hizuru and the Azumabito family. She is initially skeptical, but Zeke gives her the main body from the vertical maneuvering equipment he had procured, elucidating that the iceburst stone capable of fueling the equipment is unique to Paradis. Through an alliance, the Azumabito family would be able to take advantage of it to help restore Hizuru's power as a nation.
In 852, Kiyomi visits Paradis Island as a special envoy. She meets Mikasa Ackerman, who is surprised by her similarity to her mother. Mikasa shows her the Azumabito family crest tattooed on her wrist and is complimented on this. She reveals that Mikasa is the last descendant of a Shogunate branch that had settled upon the island, and is therefore directly related to the Azumabito family. In a meeting, Kiyomi goes on to explain a method in which the island would catch up with the rest of the world.
In 853, the Azumabito family replies that they are not willing to help Paradis Island trade with other nations because they want all of its resources for themselves.
One month after the Marley Mid-East War, ambassadors from across the world are invited to a festival in the Marleyan city of Liberio. Of these ambassadors, at least one is sent from Hizuru. One of these ambassadors is Kiyomi Azumabito. Udo, a Warrior candidate, accidentally spills some wine on her kimono during a gathering on the eve of the festival. Fearing for Udo's safety given his Eldian heritage, Kiyomi claims that she had spilled the wine on herself and was asking the boy for assistance. As she departs, the other candidates serving the ambassadors are surprised by the benevolence of the ambassador.
Before the curtain rises for Willy Tybur's speech, Kiyomi visits him backstage. Willy welcomes her on behalf of the whole Azumabito family, and is praised by Kiyomi for his bravery. She prays he is able to successfully fulfill his duty, before leaving the festival in its entirety.
After the Raid on Liberio, Kiyomi returns to Paradis Island and meets with Darius Zackly, in preparation to witness the Titans' rumbling. Following Zackly's assassination, Kiyomi is instructed to stay by the harbor for her own safety. She talks to Mikasa, who correctly accuses her of not caring who is in charge of the island, as long as the rumbling test is a success. Kiyomi admits that this is true. If the rumbling test turns out to be unsuccessful, it is likely that Hizuru would claim plausible deniability, stating the Azumabito family had acted without permission. Due to the large amount the family had invested into the plan, as well as their heavy debts, she believes this would ruin them. Despite this, Kiyomi insists that protecting Mikasa is a genuine concern for her family.
After Mikasa saves Kiyomi and the rest of the engineers, all of them retreat to the basement with Magath, Hange Zoë and Jean Kirstein. The Azumabitos then reveal that it would take half a day to get a flying boat ready which could mean doom for Liberio, however, Kiyomi suggests going to Odiha by boat and preparing it there.
The Azumabito engineers run onto the battlefield in order to try to make it to the boat; however, the Yeagerists fire gunshots and thunder spears being fired at them. The Female and Armored Titans are forced to save them using their body parts. After they reach the boat the engineers help Onyankopon to get the boat ready.
- The family crest of the Azumabito family is a circle with a triangle made up of three samurai swords inside, as homage to the family's Shogun roots. It is sewn to their clothing and even tattooed to their skin.
- A common stereotype is that the Azumabitos are sensitive to the smell of money.