Regular at the Time of Eve café. Has womanly sensuality. She and Koji are always together and make a somewhat unbalanced couple. At times she seems kind of ill at ease. Seems to be strongly possessive of Koji, and never lets go of his arm when they are together. (Source: Official Website - English)

Spoiler

Rina is a female-form android bodyguard who has been illegally modified to perform as a sex-bot. She was formerly owned by a VIP, who abandoned her during an assassination attempt. Her right leg was damaged while she was attempting to protect her master, and it malfunctions periodically, threatening to reveal her identity as an android. Since she's been illegally modified, she cannot be sent back for repair, and is technically on the run from the authorities. She won't seek help because her existence would embarrass her master. Rina and Koji each believe the other is human, and their relationship is dependent on this assumption. (Source: wiki)