Kokoro

Kokoro (ココロ) is one of the main characters in DARLING in the FRANXX series. She's a Parasite with codename "556" of Thirteenth Plantation, where she's partnered in boy-girl pair with Futoshi to pilot a FRANXX called Genista.

Appearance
A beautiful girl with long, wavy, ashen blonde hair and rich blue eyes. She wears a lacy blue headband to keep her hair out of her face.

Personality
A very gentle soul with a kind personality to match. She doesn't speak too often, but when she does her words are well thought-out and meaningful. Her FRANXX partner is Futoshi

Etymology
Kokoro's nickname may use some of the numeral's readings from her real name "Code:556": ko, an alternative spelling of "5" and ro as in 6.

Kokoro is also the japanese word for "heart"