Ranko is Yukana's childhood and best friend and also in love with her however, due to her protective nature over her she is willing to commit violence or even use underhanded techniques to make the people who either have ill intentions towards Yukana or even showing romantic interest in her such as offering sex or just straight up fighting them as she's physically stronger than she looks. Ultimately at heart she is a good, loyal friend, albeit sultry and sexual as part of her nature.