Ranko is a serious woman who always holds a neutral, if not, threatening, expression. Her stoic manner isn't quite popular with the customers, but that doesn't stop Ranko from being a professional.
She always carries a stern, professional demeanor, whether serving patrons at the café or gunning down rival maids. She doesn't get upset when people insult her, but she gets offended if anyone insults the café or her coworkers.
Underneath her stoicism, it is implied that she seems to suffer from survivor's guilt. Ranko has openly stated that she's distrustful of people, does not care for her life as long as she can serve her café, and had given up at happiness when she signed into the maid life.
(Source: Akiba Maid War Wiki)
