Rikka Takanashi is a "chūnibyō patient" who enrolls into the same high school as Yuuta Togashi. Unlike Yuuta, she still suffers from the eighth grader syndrome. She believes she is a sorceress possessed by the "Tyrant's Eye" that will reveal destinies. She wears a medical eyepatch over her right eye to seal her "Tyrant's Eye". Those who have seen her "Tyrant's Eye" are considered as completely signing a contract with her. She moved in to the apartment above Yuuta's apartment to stay with her sister, Tōka Takanashi.