Kuzuha Togashi is the younger sister of Yuuta Togashi and the middle child in the Togashi family, positioned between Yuuta and her younger sister Yumeha. She is three years younger than Yuuta, making her 13 in the anime's first season, 14 in the second season, and 15 during the movie. Her appearance features neck-length black hair, green eyes, and a height of 143 cm. Fully aware of Yuuta's chūnibyō past as the "Dark Flame Master," Kuzuha found his middle school phase deeply embarrassing. Years of exposure, however, accustomed her to his delusions. One evening, tasked by their mother to visit a stationery shop, she reluctantly accepted Yuuta's escort only for him to appear in full "Dark Flame Master" regalia, including an airsoft shotgun. When encountering her friend Mika en route, Kuzuha desperately tried to hide Yuuta's presence. Mika eventually spotted him and called him "cool," unaware of his background. This briefly made Kuzuha question her perception before reaffirming her preference for his ordinary self. Kuzuha displays a responsible and level-headed personality, often taking on household chores like cooking. This responsibility increases due to her parents' frequent absence, requiring her and Yuuta to manage the home together. Sharing her brother's laidback demeanor, as noted by Shinka Nibutani, she exhibits a pragmatic view of Yuuta's relationship with Rikka Takanashi. She bluntly dismissed her mother's teasing about feeling like her brother was being "taken away," stating she had no such feelings, and occasionally offers observations that lightly embarrass the couple. Her father works abroad in Jakarta and is largely absent from daily life, while her mother is rarely seen. During the events of the Rikka Version movie, Kuzuha, along with Yumeha and their mother, moved to Jakarta to live with their father. She later returned to Japan in the second season to continue her education, temporarily residing with Yuuta and helping manage the household during that time. Kuzuha's role in the original light novels is minimal, confined to a brief appearance in Volume 2's final chapter. The anime adaptation significantly expands her presence, featuring her from the first episode onward and in ancillary content like the Lite episodes. Her status remains consistent as a first-year junior high school student across all appearances.