In a park swept by wintry winds, a girl named Ai plays her euphonium. Her melody carries a melancholy, bittersweet tone. Burdened by her sense of duty as club president, she steels her resolve—she tells herself it's okay to endure this alone. For the sake of the national competition, and for her adorable junior members, she accepts a sorrowful sacrifice. Conducted by the hardened penis of adult men, an obscene harmony begins. Again and again, semen floods her vagina, emotions intertwining as one. Now, the curtain rises.