Rina came to Tokyo relying on her older sister, Maya, who is married and living there, and is living as a freeloader at her sister's house. The husband, who is worried about the responsibility of entrusting his daughter of marriageable age, watches his sisters blossom as they talk about their recent boyfriends. Despite such worries, while sending Rina home from a date, Saeki, who dutifully came to greet them, is a friendly man... However, this man, while appearing serious on the surface, is actually a womanizer. He lusts after Maya without any morals...
