The scenery of everyday life changed completely after that day. Hayato, a childhood friend, comes to visit her husband, whom she regards as her "brother," up to three times a week. However, Hayato's true intentions are different. It's to meet Misaki, who she has feelings for. Misaki, who doesn't realize Hayato's feelings, casually asks him, "Do you have a girlfriend...?" and things start to move with a bang.