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