She said, "I love being tied up and left alone." Ever since she was 19, coming to this room became a habit—she's lost count of how many times she's been here. Now she's twenty. "Once I'm bound, something strange happens. I end up doing anything. Do I become a different person? Or was I always like this?" she wonders. Secretly, without telling her boyfriend, she's gradually sinking deeper into this world, torn between pleasure and anxiety. "My master promised me," she murmurs, "that if I break up with my current boyfriend, he'll put a collar on me and keep me as his own." With a delicate, blushing smile, Rika's training documentary unfolds.