Ozu and her lived together as a young couple in Kotoura and had Guano. When Ozu returns from going to make his fortune, he discovers that both her and their son have gone missing and the house is in somewhat ruins.
It is never revealed what happened to her after that day; however, on the official Kappa Mikey website, it is mentioned that "Guano's side of the story had yet to be told". However, due to the series ending at two seasons, Guano's backstory was never explained.
In "A Christmas Mikey," Ozu sort of implies she is gone since he only talks about he has thought of only his long-lost son and is surprised he wasn't gone forever. It is assumed then that since she hasn't appeared in the present day that she passed away somehow.
- It is possible she was named after the wife "Kiyoko Hirayama" in Equinox Flower, directed by Yasujiro Ozu (whose name also could be named after Ozu).
- Kiyoko is a popular female's name in Japan.