In this story, there is a girl named Yukina Kaneshiro, and she is going to a party with her friends. When she arrives at the party, she finds that it is strange, and she also finds that there are some people who are missing. She thinks that it is strange that there are so many people who are missing, so she starts to look for clues. 

In the party, there is a masked man, and he says that there has been a murder, and he wants to play a game with the girl. He also says that the rules are simple, and that he will tell her what the rules are.

The rules are that, every three days, you will need to vote for someone to be executed. If you vote for the right person, you can go free. The game will continue until the killer is found. 

If you don't know who the killer is, you can find out by finding out who is missing. You will also find out more about the party, and what happened.