She is voiced by Haruna Ikezawa in the Japanese version while in English she's voiced by Monica Rial.
Momoka has peach skin and sky blue hair with mulberry eyes. She mostly wears her clothes as with puffy sleeves. In the 2014 anime remake, her hair is lighter and she doesn't wear any puffy sleeves like she did in the original anime anymore.
In this form, she appears as a cute, polite and shy and sweet girl (based on her mother and father); and she is too weak that she cannot unleash her true power.
Her second form, which is her signature personality, is brutal, hot-tempered and incredibly strong (based on her mother). In this form, the spikes on her hair become pointy and her eyes change appearance.
Most of her history is quite unknown, except the fact that she met Tamama but never had physical contact when she was around 7–8 years old in the 1st grade. She also revealed in chapter 140 of the manga that she lived in France for two years.
- Momoka has a best friend named Shion, who lives in France who uses the dragon book from her deceased parents and has an alien partner named Terara, which commonly reflects her personality.
- Momoka can be shown as very abusive, because she is often seen beating up Tamama frequently.
- Whenever she sees people blocking Fuyuki's way, she will violently push them out of the way.
- Nishizawa also has a robotic suit she uses in combat. She used it multiple times in the old anime, however she used it once in Episode 8 of the 2014 remake and it was never seen again shortly afterwards.