Xiaoxia, who was studying in the United States, was called back home by her mother during the semester because her father was seriously ill. The plane encountered an inexplicable turbulence during the flight. When she woke up, she found that she had traveled to Japan at the end of the Tokugawa period, and also landed in Tosa, a place where poor people gathered and the hierarchy was strict. She has become younger, has a language barrier, and is recognized as her younger sister by a somewhat scary-looking ronin. What should she do?