Ruriko Kouda is the mother of Mikako and Miwako. She often acts more like a co-dependent elder sister than a mother, while Mikako does most of house work to maintain their home life. Ruriko works as mangaka (manga artist) in shoujo genre. Ruriko's best stories are love stories where the main character is a poor, young and helpless girl. She is shoujo manga artist, who is considered number one in composing sad and painful love stories and really is popular.
Ruriko is night owl and is often seen sleeping the morning away, after all-night drawing shoujo manga. The title of manga series she works througout this story is "Fantasia for Two".
When Ruriko gets pregnant with Miwako, it's shown that she is 38 years old, so she had Mikako when she was 21 .