Shin, having entered university, lived as a lodger in the house of his beloved aunt, Yumi. However, his faint hopes shattered in an instant one night when he secretly read her diary. Inside, he discovered her unwavering feelings for a man she loved, with proof that she had shaved her pubic hair for him. Even after the man left, she continued the habit, indulging in nightly masturbation to deepen her longing. Filled with frustration at being unable to fill the void in Yumi's heart, Shin grew restless. Yet unable to let go of his feelings for her, he decided to take action.