Himehibi: Another Princess Days ~White or Black~

Kisakino Emi is an orphan attending a local high school and living a quiet, average life. Then an invitation arrives from the wealthy Sumeragi corporation: they want a girl — a "Princess" — to spend a year at their elite all-boys school as part of a top-secret test to evaluate whether the school should go mixed-gender. The conditions are strict: she cannot tell friends or family, all her outside communication is cut off, and she must live on campus as the sole girl among hundreds of boys. The Rapunzel of Sumeragi Gakuen. A reverse-harem otome visual novel about a girl dropped into a world she never applied for.