|First appearance||Episode 160 (anime)|
|Voiced by||Yoshiko Sakakibara|
|Species / Type||Pekoponian|
Oka is a very talented fighter. She held a martial arts competition where suitors have to defeat her. Only Baio was able to defeat her, and she later married him and had a child, namely Momoka.
She appears only rarely as she is often traveling the world on a training journey. Many of her infrequent returns to the Nishizawa mansion involves her testing its defenses. If she can make it past all of the guards, the entire security force is fired (this has apparently happened several times).
Just like her daughter, Oka also has a split personality though hers are the reverse of Momokas'; the usual personality is harsh and violent while the inner personality is reserved and polite, though the inner personality tends to show up only in private moments and has only been seen talking to another person once (in the manga).
Oka literally means "cherry flower".