High school baton club seniors and juniors "Itsuki Ayahara" and "Miku Himenono." Miku had long admired Ayahara, and fifteen years later, she received an unexpected dinner invitation from him. Excited, she visited his home. The two ended up bathing together, and that night their relationship crossed the boundary of senior and junior. Married Miku confessed, "I've never done this with my husband—let's do it together." As Ayahara stimulated her anus—something her husband had never seen—and asked her to urinate for him, her feelings for him deepened. Finally, Miku declared, "Senpai, please give me your urine!"