After Yuta's father lost his job, his sister Rei's income became the lifeline for the whole family. Since then, Rei has been like a 'Queen' in the house, with all the others being her servants, parasites clinging to her. One day, because his company went bankrupt, an old friend of Yuta's came to leave some things at his place. He said it was vitamins, so Yuta didn't suspect much. Feeling a bit tired lately, Yuta tried some of his friend's vitamins and to his surprise, his penis immediately became erect! Knowing that this drug was very suspicious, Yuta decided to use it to take revenge on his annoying sister!