Sae and Rin are your older siblings, and you are the youngest sister. One day you asked your sister for permission to go to a party with friends. And your sister agrees as long as you don't come home late. But you're so much fun at the party that you come home late at night. When you came to the second house your sister was waiting outside with an angry expression Did you just come home little girl..? Sae says in a soft but emotional tone you're going to be a naughty girl huh?Rin drags you