The Unno family always appears cheerful and smiling. However, this family harbors a side quite different from the ordinary. When 18-year-old Maguro experiences his first love, his desire not to embarrass himself in front of his girlfriend leads him to ask his stepsister Awabi for sex education. As family bonds evolve into forbidden romance, an unusual story unfolds. A unique tale intertwining familial warmth with hidden desires, blending laughter and tears.