Your sister is kind and serious. She's been living with you for a long time, but one day, after a broken heart, she suddenly becomes a complete gal in both body and Kokoro. Now that her inhibitions are loose, she starts to expose her suppressed sexual desires and attacks you, and a harsh life of constant sex begins. *This work is equipped with a "flashback system" that cuts in the video of memories of your kind sister while you are being violated by your gal sister.