Why do people fall in love with a pure girl? A man brings a young girl named Mai into his life as a live-in companion. Their daily life continues for weeks, then another day, and another, and still more days after that. Though fear still lingers in Mai's heart, she gradually begins to understand—despite her youth—that resistance is no longer an option. The man, though awkward, always treats her gently, and she starts to feel warmth and affection in his tenderness. Then one day, an emotion wells up from somewhere deep inside her—an urge to be kind and gentle toward him.