At first, she was only helping her little brother with his masturbation... but before she knew it, she had crossed the line and fallen in love with him. Her birthday present to him is a 'first sex coupon.' Virgin and virginity, sister and brother's first experience. However, troubled by his relationship with his sister, he tries to start dating a female classmate. 'Drink your big sister's piss!' And then forced ●● internal ejaculation. The twisted daily life of love between the sister who loves her little brother too much and him.
