Chacha is an MSA Android who intends to use the Nano List technology to subjugate humans. Chacha enjoys a position of influence at MSA and employs other Androids to help realise her schemes. According to Dr. Ahn she is under the protection of the head of MSA.
She admired Dr. Maddie Ahn and shared a camaraderie with her during their collaborations but attempted to hack the research behind the doctor's back. After getting caught and rebuffed by Dr. Ahn, she resorted to coercion which ultimately failed. She was considered a mother, a wife and everything to the CEO of MSA. In a flashback, it was revealed that she has known the CEO since his infancy and that he himself is obsessed with her and allows her to do whatever she wants even striking against him. She was shown to have slapped the CEO multiple times throughout the series and the CEO who punished others for calling her a “piece of junk”. She was also shown to have disliked her master and wanted to break free from his control but couldn’t due to his order of staying by his side forever