She's one of the eight princesses of Valhalla, and she constantly refers to herself as a cyborg, though Hydra and Laine consider her as just plain nuts; In reality, she's one of those kinds of people who take fiction way too seriously. She makes a cameo in the first series and plays a major role in the second season. Chorus likes to go on the Internet in Rika's closet, much to Rika's annoyance. She has the ability to feel psychic wavelengths and can even make them into pictures by using a computer printer. In the Anime, Chorus makes direct references to other anime.

Source: Wikipedia

Chorus is the only person other than Kazuto who can feel the sadness of the four lost princesses of Valhalla, and realizes the truth behind the appearance of Valkyrie Ghost. After coming to terms with her emotions, she starts living with Laine in a western-style wooden mansion.