As a college student, I was invited to her house for the first time and introduced to her younger sister, Hina. - Hina-chan, who looks sober and serious, is shy and doesn't talk much. - That night, I got married to my girlfriend, but Hina, who we passed each other in the hallway, suddenly pressed her body against mine and whispered in my ear, "I'm more erotic than you..." and put her hand on my crotch. - I let it slip in. - Then, she smiled as if toying with me and began to show her lewd nature by repeating obscene words that I couldn't even imagine from her appearance...