Togo Jun and her younger sister Mishima Ran meet again for the first time in 13 years at the funeral of their mother. Since Jun was a child, her free-spirited younger sister, Ran has taken away important things such as her favorite clothes, accessories, and toys. What's more, Ran even married Jun's ex-lover, Ritsu Mishima. Since Jun can't let Ran take away anything more precious to her, she decides to live with them both. Gradually, the sisters engage in a fierce battle over one man!

Jun was always told by Ritsu that he had wanted to meet her, but in front of Ran he acts as if nothing has happened. At the same time, the old emotional wounds of Ran having everything important to her taken away come back to haunt her. One day, Ran is preparing for a big housewarming party for many of her friends, but Jun warns her that she is insensitive even though her mother has just passed away, and her sisters are once again in trouble. And through the party, the reason why Ran is trying to take everything away from Jun is revealed.

Ritsu's interest in Jun has increased since they kissed. However, he suppressed his feelings, making Jun sad. On the other hand, Ran, who lives with these two, is driven by anxiety that Jun will take Ritsu away from her, and the relationship between the three becomes increasingly chaotic. Why is Ritsu worried and wavering between Jun and Ran? Time goes back to Ritsu's childhood, and the reason for this is revealed.

Jun and Ritsu finally manage to sneak out of the house together, and that's when they tied the knot. When the two returned home the next day, Ran asked them about what had happened the night before, but they pretended to be calm and lied, and it seemed like they had gotten away with it. An unexpected person comes to the hospital and the story changes completely. Furthermore, what is the shocking truth that Ritsu tells about 13 years ago?

Jun is furious when he learns of Ran's lie from 13 years ago. However, even though she tries to take out her anger on her sister, she is stopped by Ritsu. On the other hand, even though Ran realizes that Ritsu has revived his feelings for Jun, she vows to keep Ritsu's relationship with her no matter what she does. One day, while discussing Ritsu's affair with Hikaru, Ran suddenly feels nauseous. From that moment on, Ran's plan begins.

Two weeks have passed since Ran left home, and the Togo household has become as quiet as if a typhoon had passed. Jun, who is having breakfast with Ritsu, becomes so aware of Ritsu's presence that even the sound of his footsteps makes her heart flutter. On the other hand, Ran, who cannot give up on Ritsu and wants to get him back from Jun, is torn between her feelings for Ritsu and her mother.

Ritsu suddenly sheds tears in front of Jun and says that he wants to meet Ran. Jun feels sad that Ritsu is about to leave her again. In the midst of all this, she receives a call from her aunt, Natsuko, and is reminded that her mother's interment ceremony is coming up next week. Meanwhile, Ran was unable to reply to Ritsu's message, which she had been waiting for for a long time. During a conversation with Hikaru, Ran begins to realize her true feelings. On the day of the interment ceremony, she was thought to be absent, but she appeared in front of Jun.

Jun is perplexed as Ran tries to break the spell of her family on her own. Meanwhile, Ritsu is given divorce papers by Ran and is left dazed. Jun is left behind by the two, and she begins to regret that the "correctness" she has been forcing on others may have cornered someone else. One day, a strange man appears in front of Jun, and Jun is at a loss for words.