Euphonium player "Ai," a cute short-haired beauty from the school's concert band preparing for the national competition, draws attention as an innocent girl. While being teased by older men, she's tormented in her school uniform, her sensitive body overwhelmed with unbearable sensations. For the sake of her junior members, she has no choice but to sacrifice herself. Surrounded by numerous men, she's treated like a toy, forced to perform sweet, submissive blowjobs as they touch her erect dick. Ultimately, she faces the forbidden pleasure of creampie—her ultimate ecstasy.