Hitomi Tadano is Hitohito Tadano's energetic younger sister. She shares his black hair and eyes but is shorter and slimmer, typically wearing her hair in two short twin tails. Her confident, outgoing personality starkly contrasts with her brother's reserved nature. She acts without concern for others' opinions, exemplified by introducing herself through rapping and openly admitting her academic and athletic struggles during class introductions. Despite being perceptive about feelings and social dynamics, she sometimes misinterprets situations, such as mistaking Shousuke Komi's silence for a communication disorder rather than intentional avoidance, leading her to use ventriloquism to "help" him speak. Her forthrightness and cheerful demeanor make her well-liked among peers, though her enthusiasm can occasionally overwhelm others. Hitomi lives with her parents and brother in a small apartment, sharing a room with Hitohito. They use bunk beds, with Hitomi on the top bunk, and follow a "barrier" rule for privacy. She refers to her brother as both "big brother" and "Otsu." Family interactions include collaborating on anniversary gifts for their parents and preparing Valentine's Day chocolates for Hitohito. She frequently teases him about his romantic life but also supports him, encouraging confessions and assisting with gift selections for Komi. Academically, she attends Kisai High School, progressing from third-year middle school to second-year high school. She serves as a class representative and actively participates in school activities. Her abilities include ventriloquism, proficiency in judo (having competed in prefectural tournaments during middle school), skill with digital devices, and soccer. Throughout the series, she greets Komi and friends during a study session, takes and shares a photo of Hitohito cross-dressing at a maid café with their mother, and orchestrates situations to facilitate interactions between Hitohito and Komi, like sending him out to meet Komi on Valentine's Day. She develops a subplot romance with Shousuke Komi, whom she initially mistakes as having communication issues. She refers to him as her "little brother" and manages his schedule, creating event boxes for Valentine's Day chocolates. Her perceptiveness extends to deducing Komi's feelings for Hitohito; she devises code names like "A," "B," and "C" to analyze the love triangle involving Komi, Hitohito, and Makoto Katai. However, she initially misinterprets Hitohito's romantic interest as directed toward Katai. After Hitohito and Komi begin dating, she becomes supportive of their relationship. Recurring family misunderstandings occur, such as their mother overhearing partial conversations during White Day preparations and mistakenly believing Hitohito received chocolate from a boy. Hitomi demonstrates protectiveness, suspecting Hitohito's interactions when she smells a "girl's" scent in their apartment after Komi visits an ill Hitohito.