Kotomi, a member of the school's vocal music club, has been studying piano since childhood. Always cheerful and smiling, this schoolgirl harbors a deeply hidden, insatiable sexual desire. With a strong masochistic tendency and extreme sensitivity—so intense that wet marks frequently appear on her panties—her body reacts powerfully to stimulation. Subjected to relentless, intense sexual torment by a highly enduring male performer, she twists her face in overwhelming ecstasy, climaxing repeatedly. Here, her pure singing voice contrasts with raw, unleashed passion, revealing her true nature.