|The Azumabito clan had no choice but to adapt to these turbulent times. But as a result, our prestige has been reduced to the point where we're now derided as a pack of wretched, money-grubbing vixens... Still... We haven't lost our pride any more than your mother had when she engraved our crest into your wrist. No matter what becomes of this land, we truly wish to protect you.|
|— Kiyomi pledges to protect Mikasa|
Kiyomi is a middle-aged Asian woman. She is around average in height and has small facial features, thin eyebrows, and black hair neatly kept in a bun.
When fulfilling her ambassador services, Kiyomi usually wears the traditional Hizuru kimono, though she still dresses formally otherwise.
Like many from the Azumabito family, Kiyomi is sensitive to money. She is easily bought to ally herself with Paradis Island after hearing about its iceburst stone reserves from Zeke Jaeger. The mere thought of wealth causes her to salivate. Despite her greed, Kiyomi claims to have a strong sense of pride for the Azumabito family as seen by her desire to protect Mikasa regardless of the Azumabito's investments in Paradis Island.
Kiyomi is a calm and secretive individual, playing along with Willy Tybur's festival and even congratulating him despite knowing what is to come. She also is sympathetic to Eldians, as shown when she chose to cover up Udo's mistake of spilling wine on her kimono, saving him from the other ambassadors.
Some time between 850 and 852 Kiyomi meets with Zeke Jaeger, who explains his wish to restore his ancestral homeland of Eldia and how helping him would in turn benefit Hizuru and the Azumabito family. She is skeptical at first, but Zeke offers ODM gear that he has personally procured. The iceburst stone that fuels it is a uniquely powerful resource that Hizuru would be able to take advantage of and make it a powerful nation once again.
In 852, Kiyomi visits Paradis with a diplomatic delegation from Hizuru where she discovers that Mikasa Ackermann is the last descendant of a son of her nation's shogun clan, from which the Azumabitos are also descended. She calls the passing of the family crest by Mikasa's mother to her daughter, and Mikasa's intentions to pass it on to her own children, a noble act.
Kiyomi explains her arrangement with Zeke to the Paradis military and outlines the three processes by which the island can be saved. Her part is in the second process. Hizuru will work with Paradis to bring its level of technology up with the rest of the modern world. She estimates that it will take fifty years, which is why Paradis will need their queen to inherit the Beast Titan from Zeke and bear as many royal children as she can in her remaining thirteen years. This will hold the rest of the world at bay until their technology can catch up.
In 854, the Scouts visits Marley in order to attend the "Association to Protect the Subjects of Ymir" international forum. While staying at Kiyomi's house for the night, they discuss the state of the Subjects of Ymir outside the Walls and Kiyomi shows concern over the possibility of Paradis forming friendly relations with other nations.
In 854, Kiyomi attends the party the night before the festival in Liberio. She meets Udo, one of the Warrior candidates, when he accidentally spills wine on her kimono. Understanding that he would quickly get in trouble for this, she warns him not to make a scene and passes off the spill as her own mistake.
The following night, Kiyomi visits Willy Tybur in the backstage area where he is preparing for his stage production. She passes off her visit as simply wanting to see his face and calls him a brave man, a fact her family knows well. Kiyomi tells him that she hopes he fulfills his duty without incident, but after she leaves, she tells her escort that it is time for them to go, and she does not stay to watch the production.
Kiyomi goes to Paradis Island and is greeted by Dhalis Zachary. She congratulates the nation of Eldia on its victory at Liberio and informs Zachary that she has brought a flying boat which uses iceburst stone as fuel with her.
Kiyomi is present during a tense Paradis military meeting. After Pyxis dismisses the soldiers, he goes to her and apologizes for having to see the exchange and asks her to stay by the harbor for her own safety.
Before she leaves, Kiyomi gets ahold of Mikasa and asks her to escape on the Azumabitos' ship if she is worried for her life. Kiyomi explains if the Rumbling does not succeed, it would spell the end for the Azumabito family, as Hizuru would leave them out to dry. She laments the stigma of her family becoming greedy and scheming vixens, but still holds the pride of their clan and assures Mikasa of her desire to protect her.
After Eren Jaeger begins the Rumbling, Floch Forster and the Jaegerists take Kiyomi captive at the island's harbor to try to coerce them into contributing to Paradis' interests. Although Floch begins executing her companions, Kiyomi is unperturbed and instead points out to him that Eren's plan to destroy the outside world will not stop the Eldians on Paradis from infighting.
When Conny and Armin arrive at the harbor, Floch decides to execute the Azumabito mechanics so that they cannot be used against the Jaegerists. Kiyomi intervenes on her companions' behalf, disarming Floch and leaving him subdued on the ground. Mikasa arrives to help dispatch the rest of the Jaegerist guards, but Floch manages to escape. Mikasa leads Kiyomi and her companions to the basement of the building, where they will be safe from the ensuing battle.
While hiding, the Azumabito mechanics reveal that it will take at least half a day for them to prep the flying boat for launch, to their saviors' distress. Kiyomi suggests taking the boat to the island of Odiha to perform maintenance, as they will have better odds with the equipment on the island. The soldiers agree, and Kiyomi and her mechanics run for the boat, boarding it while their allies defend them. With the help of others' sacrifices, they successfully set sail for Odiha with the flying boat.