Mio Shimazu

Mio Shimazu is a senior at Sakaimachi Academy and the only daughter of the town's mayor. Despite her privileged upbringing, she strongly resents being labeled a 'young mistress' and struggles to openly express her feelings toward the male protagonist, embodying a classic tsundere personality. Driven by a deep fascination with history, she dedicates herself to investigating the so-called 'Four-Hundred-Year Cycle Theory,' frequently conducting fieldwork at Cape Tsurugi. In the modern-day story arc, she serves as a vital ally in unraveling the mysteries of the past.