Originally blunt, stubbornly introverted and unempathetic beyond her immediate family, Rui develops through her teenage years thanks to a loveless one night stand, a new step-family, a close set of newfound friends in the literature society and her first experiences of love. Learning to navigate unrelenting, messy and undiscovered emotions, Rui's character is defined by her growing openness and honesty to her friends and the wealth of lessons on life and love she discovers in the process.

Rui enjoys traditional Japanese music, to the chagrin of everyone else in the room during karaoke. She also has a passion for cooking. She likes cats: she uses a black cat as her profile picture on her phone.