高槻 沙希

She is the youngest daughter of Takatsuki Seiichi, who served Kazuki's father. Due to their fathers' friendship, Kazuki and Saki have known each other since childhood. She is usually cool and doesn't change her expression, and is the only person who can tell Kazuki off, but no matter how she is treated, she has a strong love and loyalty for Kazuki. This is not just because her father instilled loyalty to the Tsukamoto family in her, but also because she has admired Kazuki since childhood and is grateful to him for saving her life, and it has even become her "meaning of life" that has been accumulated through all sorts of events. The Takatsuki family has served the Tsukamoto family for generations, but her three older sisters did not want to take over Seiichi's business and married into ordinary families, while Saki's desire was strong, so she became the heir and serves Kazuki. Saki's father has commanded her to "leave an heir of noble bloodline and never cut ties with the Tsukamoto family," but she only has eyes for Kazuki and thinks to herself that "the Tsukamoto family also falls into the category of noble families."