Kiyomi is a beautiful young woman. She has long light hair with bangs tapered to the sides. The top of her hair seems to be braided on the sides and back of her head. She is only shown wearing a swimsuit while on the beach.
Kiyomi is irresponsible and neglectful toward her son. Instead of going to work, she would take several days off and relax on the beach. She goes as far as taking Unisom sleeping pills before calling her workplace to feign sleepiness.
She also doesn't bother saving her own son and watches him drown. Although she appears worried initially, Kiyomi thinks it may be better to let Josefumi die so she could be free, as two men previously stopped flirting with her after seeing she has a kid. After Yoshikage Kira saves Josefumi from dying, Kira points out that Kiyomi looked like she was feeling something else rather than relief. Despite her negligence, and after seemingly abandoning him, Kiyomi kept photos of Josefumi on her phone, still looking for her son.
At some point, Kiyomi and Sadafumi Kujo got married and had a son named Josefumi Kujo. When Josefumi was a toddler, she and Sadafumi got divorced. Soon after, this took a heavy toll on her, as Kiyomi would constantly take days off from work, feigning illnesses or headaches, and would do other things instead like go to the beach.
One day while on the beach with Josefumi, Kiyomi is invited by two men to a party but they change their mind after seeing she has a son. She takes sleeping pills and then calls her workplace again but her boss fires her for being continuously absent. After the call, she sees Josefumi suddenly drowning in the sea. Kiyomi is initially hesitant but dashes toward Josefumi. However, she merely watches him drown and he is only saved twenty minutes later.
She is brought to TG University Hospital where Josefumi is given emergency treatment by Holy Joestar-Kira and Yoshikage Kira. She remains in the waiting room, fearful over whether or not Josefumi survived, until she is informed by Kira that her son is all right.
At some point, Kiyomi has another child. While at TG University Hospital, Kiyomi drops her phone while carrying her baby. Yasuho Hirose and Josuke Higashikata notice her after leaving the hospital. Yasuho helps her by picking up her phone on the ground. Thanking the two, Kiyomi leaves and walks to the hospital. Yasuho immediately recognizes the woman, and Josuke mentions that he already knew based on the descriptions given by Karera Sakunami and Tamaki Damo. Despite Josuke's assumption that Kiyomi had forgotten about her son after the earthquake, it's revealed that she is still looking for Josefumi and kept photos of him on her phone.
- “I'm really sorry. I've been feeling awful this morning. I think I've got a pretty bad headache, too... I really am sorry, but I'd like to take my shift today off...”
- “I wasn't lying... That was the truth... My head really does hurt... I'm tired... I've gotta straighten up... I'll start working hard tomorrow.”
- “Didn't mommy tell you that she'd get mad if you went too far?!”
- "Kiyomi" (聖美) has the same first kanji as Holy Kujo's Japanese name, "Seiko" (聖子, lit. Holy).