It targets the common trope of the "beautiful older neighbor/tutor" who takes an interest in a younger man.
: As a visual novel, the story is told through character dialogue and narrative descriptions, often featuring different story paths based on the format. Anime Adaptation Katekyo -Kireina Onesan to Himitsu no Lessons- ...
Much of the tension comes from keeping their evolving relationship hidden from parents, classmates, or the public. It targets the common trope of the "beautiful