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.
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.
Her relationship with Josefumi becomes nonexistent after the incident, as Josefumi mentions that he was abandoned.
- "Kiyomi" (聖美) has the same first kanji as Holy Kujo's Japanese name, "Seiko" (聖子).