You are Isao Komori, a college drop out and shut-in, you usually play video games all day but when you go to the nearby convenience store, interesting things happen. When you get to the store, you see a high school student named Mari, a beautiful woman, she doesn't notice you at all but she's like an angel

One day, you find yourself in Mari's body, but Mari's consciousness isn't in your body, so your body acts like you while your actual mind is in Mari's body