A mysterious girl encountered by Hyougo Otoo during his travels, Aoi Yamada initially presented herself as a 16-year-old orphan whose parents died in a house fire, possessing only a luxury suitcase. Otoo brought her to Wagnaria restaurant, where she began training as a waitress and lived in the attic. Her fabricated background soon unraveled due to inconsistencies such as her delayed response to the name Yamada and the implausibility of salvaging a fully packed suitcase from a fire. Investigation revealed she had run away from home following conflicts with her older brother, Kirio Yamada, primarily over him eating her favorite natto. While her real first name, Aoi, was genuine, Yamada was an alias. Her personality blends confidence with troublesome and blunt behavior. She intensely yearns for an idealized family, designating Otoo as a father figure, Yachiyo Todoroki as a mother figure, and Hiroomi Souma as a brother. At work, she is incompetent and disruptive, frequently breaking dishes, stealing food and utensils for her attic stash, and calling coworkers at inappropriate hours. Regular reprimands from Souta Takanashi and Jun Satou often prompt performative tears rather than genuine remorse. Academically, she struggles, failing entrance exams multiple times and misinterpreting her mother’s study aids as pressure. Her bluntness causes tensions, such as revealing Satou’s feelings for Yachiyo. Physically, she has purple hair, indigo eyes, stands 157 cm tall, and wears a waitress uniform with a trainee badge. Souta consistently sees through her deceptions, though he provides temporary shelter. Souma, after gifting her a teddy bear named Daisy, becomes a reluctant brother figure. Her actual brother Kirio searches for her for months, and her mother, Kikuno Yamada, remains caring despite misunderstandings. After Kirio locates her at Wagnaria, her mother visits and clarifies intentions about academic support. While some misunderstandings persist, Aoi gradually acknowledges her family’s kindness, though her core behaviors—stealing, clumsiness, and insistence on her constructed family—remain largely unchanged. She continues living in the attic and working at Wagnaria.