Toka Takanashi is the older sister of Rikka and knows all about Yuta's history.
Toka and her sister Rikka grew up with their family in Japan living a normal life as one can have. When she was in her late teens, her father contracted a terminal illness. Per his request, Toka and her mother kept it from Rikka since he didn't want to worry her about it as he was sick but still fine. However, things changed when his illness took a turn for the worse and died while Rikka was at school one day. As their mother had to take care of some family planning, Toka and Rikka were left in the care of their grandparents for this time. After Toka graduated, she moved into an apartment where she lived a floor above the Togashi family where she would often hear Yuta enacting his fantasies as the Dark Flame Master, recording them since she found them to be funny. During college, Toka attended culinary school where she became a chef at an exclusive restaurant in the city as she lets Rikka move back in with her to let her start high school.
Toka Takanashi does not appear in the original light novel series. She is an exclusive character for the anime created by Tatsuya Ishihara and Jukki Hanada. she makes her first appearance in Episode 2: Priestess of...Melodies. Toka is voiced by Eri Sandai in the Japanese version.