Kaoruko Yamada

Kaoruko is Renko039s quotassistantquot and thus always at her side. She is relentlessly upbeat and often tries to smooth over Renko039s temper by putting her outbursts into more tactful form nevertheless she receives a fair amount of abuse when her attitude conflicts with Renko039s serious aloof demeanor. Kaoruko also figures heavily in a variety of Renko039s inventions often as the brains of whatever device has been created for the occasion. While it not stated outright at first it becomes clear that Kaoruko herself is actually an android which explains why she interfaces so easily with Renko039s other inventions. Wikipedia