Keiko Yumeno (夢野 圭子 Yumeno Keiko) the mother of Naomi, and sister of Ittetsu Shiwakaba and the great granddaughter of Natasha. She is one of the side characters of Ultraman Orb.
Keiko first appeared to meet Naomi to "review" Gai in a restaurant, who Naomi had set up to be her "date", but only because Keiko had been begging her. While things went normal, until Juggler shows up much to Naomi and Gai's shock. Keiko immediately drifts her focus to admiring Juggler and talking to him. While Gai pulled Juggler away to talk to him, Keiko went towards them and interrupted the two of them talking by taking selfie before Naomi came and take Keiko away. After Juggler showed Gai Belial and the cards of King Demon Beast, Keiko offered Juggler food. Naomi then takes Keiko away from the restaurant, after Tamayura's spirit appears as a giant infornt if everyone in the restaurant. When Naomi was going to investigate a new matter with Shin and Jetta, Keiko appears at the SSP Office and persuades Naomi to quit her job and return home to live with her father as well. As much as Keiko tries, Naomi did not listen and wanted Keiko to wait at the office for her to come back later.
After Gai/Orb defeat by Maga-Orochi, and while Naomi and her friends decides to venture to forest of Tamayura to resurrect back Princess Tamayura to settle the issue, Keiko decides to follow them. After Naomi and her friends finished gathering the fragments of a tomb, Keiko planted seeds and watered it, allowing Tamayura to come back as the latter went on to visit Gai to give him Zoffy and Belial's cards. Keiko and the others later witnessed Orb's violent fight with Maga-Orochi as Thunder Breaster.
When Naomi was hospitalized, Keiko visited Naomi at the hospital with her uncle. She expressed her disdain over the public's negative opinion over Ultraman Orb in the light of his Thunder Breastar's rampage, believing them to be too ungrateful for forgetting the fact that Orb has saved their lives time and time again. Keiko then told Naomi to forget about Gai as he thinks that people of his type give young girls like her nothing but trouble, but not before giving her a Marythoska doll left behind by great-grandmother. Unknown to her, she indirectly allowed Gai to regain his confidence as an Ultraman and protector as the innermost layer of the said doll holds the proof of Natasha's survival when she was caught between Maga-Zetton and Orb in the past.