|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. Whatever may happen to this nation, I wish to protect you.|
|— Kiyomi Azumabito pledges to protect Mikasa Ackerman|
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 Yeager. 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 Yeager, who explains how he wishes 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 her vertical maneuvering equipment 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 Ackerman 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, drooling as she talks about the island's resources, though she promptly cleans up when one of her aides points it out to her. She then 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, Kiyomi attends the party the night before the festival in Liberio. She meets Udo, one of the Warrior cadets, 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 day, 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 Darius Zackly. She congratulates the nation of Eldia on its victory at Liberio and informs Zackly 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 Pixis dismisses the soldiers, he goes to her and apologizes for having to see this 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 in case something happens. 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 foxes, but still holds the pride of their clan and assures Mikasa of her desire to protect her.
Months before the raid on Liberio, the Survey Corps 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.
After Eren Yeager begins the Rumbling, Floch Forster and the Yeagerists take Kiyomi and the Azumabito clan captive at the island's harbor to try to coerce them into contributing to Paradis' well-being. 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 in-fighting.
When Connie and Armin arrive at the harbor, Floch decides to execute the Azumabito mechanics so that they cannot be used against the Yeagerists. Kiyomi intervenes on her companions' behalf, disarming Floch and leaving him helpless on the ground. Mikasa arrives to help dispatch the rest of the Yeagerist 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.
Arriving in Odiha, Kiyomi promises Hange to have her engineers ready the flying boat before the Rumbling reaches the city. Later that night, Kiyomi agrees to look after the two children on the ship at Pieck's request.