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, 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.