Yuka

Yuka is one of the main supporting characters in Elfen Lied.

She is Kouta's cousin and childhood friend who has been in love with him since they were kids. After Kouta moves back to Kamakura, Yuka decides to live with him (and later also with Lucy/Nyu) in his large, mostly empty family home.

Personality-wise, Yuka is generally cheerful, caring, and a bit clumsy/awkward, especially when it comes to romance. She can be jealous and possessive toward Kouta (particularly regarding Lucy/Nyu), but she's also kind-hearted and frequently acts as the more responsible "housewife" figure of the household—cooking, cleaning, and trying to keep things together despite the increasingly dangerous and bizarre circumstances.

She's an ordinary human high-school/college-age girl caught up in the violent, tragic events surrounding the Diclonius.