It's no good. There is no place of rest in this house. My younger sister said, "I got a boyfriend! But I don't know anything about sex... what should I do?", so I only taught her half-jokingly. But now, even when my parents are at home, she secretly sucks my sperm. Even the bath is no place of rest. Lately, it's rare that I can sleep properly at night. Ah, today... I brought restraints. If this keeps up, my younger sister will leave me to dry. Someone help me. [The sentence ends here]