Nana is married to her husband and is living a happy life.One day, Nana was invited to travel by her husband and came to a certain inn.Nana was supposed to enjoy her pleasant landlady and her clean room with her husband, who she had forgotten for a while.But tragedy will come.A gambling hall <Iron Betting Party> that is held in top secret at the inn.Isn't it said that her husband will participate there!What's more, the tragedy doesn't end there, and Nana turns pale when she hears the rules of the Iron Gamble.