Often called "Sis" by Kippei, Reiko is a strong-willed, bold and controlling woman. Everyone in the family follows her orders, although in truth she is just trying to do what she thinks is best for them. She is especially controlling toward Kippei and was the one who ordered that he take care of Yuzuyu.
She is a cosmeotologist and an expert in fashion. She takes great pride in her appearance.
- Misako Katakura (Mother)
- Kippei Katakura (Younger Brother)
- Satsuki Katakura (Younger Brother)
- Miyako Sakashita (Aunt)
- Yuzuyu Sakashita (Cousin)
- Reiko is physically unable to have children.
- Reiko hires detectives/officers Misaki and Kouji to help her track down Yuzuyu's mother (Miyako Sakashita).
- In the episode “Bye Bye Yellow Hat” Reiko works as a cosmetologist.