early or mid twenties, but Aria calls her 'Jiiya', a Japanese nickname for a butler, like the English 'Jeeves'. The exact reason for this is uncertain, but most agree its Aria's way of being playful. In the second anime series, it is possibly implied that Aria is simply used to calling the person taking care of her 'Jii-ya', as she points at a picture of an old man in butler's clothing, then at her maid and calls them both 'Jii-ya'. Of all the non-sister characters in Sister Princess, only Jiiya has a personal affectionate name for the sister's brother. She addresses the brother as , a more polite version of Aria's address. Featured only in Sister Princess 2, Kakinomoto is one of the handful of non-related girls allowed to be near the sisters' brother without causing any issues. She has been known to disagree with him, and played something of a devil's advocate role. A very close friend of Haruka. Has a preference to be called Pride, rather than her given name. The unnamed nurse who attends to Marie. Due to the nature of her duties and Marie's regular medical needs, she has constant contact with the sisters' brother (although not as frequent as Jiiya), and is one of the few non-sisters able to approach him without causing concern. Mecha Rinrin is a gynoid designed to be an identical copy of its creator as an experiment in robotics. In the anime, her purpose is also to lend full support to the brother in the absence of any of his sisters. Mecha Rinrin differs from her creator in her eye color and the unexplained requirement of a ball-shaped sensor on her head. Mecha Rinrin always overheats and inadvertently deactivates when the sisters' brother praises her; presumably from overwhelming joy. It appears Rinrin programmed her doppelgänger too well, as it shares an overwhelming love for him, although her delicate circuitry cannot handle the overload. In the first anime, Rinrin explains that she created her doppelgänger because she eventually intends to study in the United States. When that happens, she wants Mecha Rinrin to be there to do all the things for her brother that she herself won't be available for. Rinrin herself feels sad at the thought that she might actually have made herself redundant until she is reassured by Wataru. Also in the anime, her dopplegänger's immediate precursor is a much