Saki Mizusawa's Mistress Application: A woman who works part-time at a publishing company while attending university. She has good taste, but she has a shy personality, and she was the type to lose money. One day, she was predicted by a fortune teller who was passing by that "another you will appear", and on her way home, she suddenly felt dizzy and when she opened her eyes, she had a strange experience in which everything appeared red. And from that day on, her personality changed...