Ever since childhood, Yuya had looked up to Nana Mi as the older sister figure he admired. When he finds out she's coming to visit his home again after a long time, his heart begins to race. At first, he's too nervous to speak properly, but as they spend time alone together, he gradually opens up and their conversation flows naturally. The bond between them grows stronger with each passing moment. Fueled by alcohol, they finally lock lips in a passionate kiss—Yuya overwhelmed by his first adult kiss, Nana Mi's body burning with desire. That night is far from over. In the late hours, Nana Mi makes her way to Yuya's room. Each step she takes draws them into an even deeper, forbidden intimacy.