The protagonist Sachiko Tachibana (Nozomi Sasaki)) vows to fight against the demon-like ruthless monster Hanai Rina (Shibuya Nagisa)act) revenge.In high school, Sachiko was teased as the daughter of a murderer, and Rina became her only friend.However, behind Rina's angelic and gentle smile, there is a face of a murderous demon who easily kills people.Rina charged Sachiko and her father with murder, and also took the life of Sachiko's father.

14 years later, Sachiko, whose appearance has completely changed from her past, once again confronts Rina, who has become a new mother.“Let her taste the taste of living hell”, Sachiko enters Rina's family as a nanny.Can ordinary people who devote their lives to revenge drive monsters to destruction?A heroic revenge drama with repeated setbacks and entanglements begins. 

The nanny Sachiko Tachibana (Nozomi Sasaki) comes to the home of Rina Hanai (Nagisa Shibuya), a pianist and internet celebrity.Sachiko is interviewing Reina because Reina wants to find a nanny for her newborn daughter Kotoko (Shibata Honno).

They had many topics in common, and the conversation was harmonious, and Sachiko felt hopeful.However, due to Sachiko's inexperience, Reina plans to reject her application for employment.Rina felt a little uneasy about Sachiko who was too eager, but Sachiko noticed that there was eczema at the corner of Xiaoqin's mouth...

Sachiko greets Reina and says it's our first time meeting her, but in fact Sachiko's true identity is Bando Yukiwako (Watari Mai) who was in the same school as Reina 14 years ago.At that time, Xinghezi's father was suspected of murder, and she was laughed at every day as a murderer's daughter.But Sachiwako firmly believes that her father is innocent, and her only supporter is her school girl Rina.

Sachiwako completely trusted Reina, and one day, Reina called Sachiwako to the music room.However, when she gets there, she finds Rina holding scissors and covered in blood...!?

The next goal of Sachiko (Nozomi Sasaki) who sneaked into Reina's (Shibuya Nagisa) home as a nanny is to find evidence of Reina's crimes so far.With the information provided by her mysterious collaborator Komi, Sachiko begins to investigate the surrounding areas of Rena's father, criminal sociologist Minoru Kurokawa (played by Itao Hoshiji).

Reina, who entrusted her daughter to Sachiko, broadcast live on SNS with her influencer friends.As the story develops, Rina is used to promote a watch made by Yuko (Haruka Miwa), who is also an influencer.Although Rina just smiled and dealt with it, she seemed to miss Yuko...

On the other hand, Sachiko sneaks into the room used as a study in Hanai's house to look for evidence of Reina's crime.Sachiko was too involved, and Minoru saw her like that...!

Sachiko (Nozomi Sasaki) obtained evidence of the murder committed by Rena (Nagisa Shibuya).If there is a video stolen from Minoru (Itao Hōji), Reina can be handed over to the police, but Sachiko's purpose is to let Reina experience the taste of living hell.Sachiko plans to carry out the plan to kill Reina's beloved daughter Kono (played by Shibata Honno).Rina, who was chosen as the spokesperson for a natural cosmetics brand, was not at home due to photography, so Sachiko took the opportunity to attack Xiao...

At the same time, Sachiko's collaborator comi uploaded a video secretly filming a conversation between Reina and her agent Yuki (played by Yoshizawa Shiya). Reina received a large number of objectionable comments on her SNS.

Reina, who pretended to be calm, was actually stressed inside.Then, Rina committed the murder as easily as she was relieving herself from boredom...

Saito (Sasaki) has been waiting for the opportunity to get revenge. She witnessed the picture of Lai Nai (Takayuki Aya) holding a kitchen knife to Xin Nai (Zhitian Feng Nai).Saezi realized that Lina has always believed that“of his own children are particularly”. The premise is wrong, so she and mysterious collaborator Xiaomei re -developed the plan.

Lai Nai, who had been interested in Xin Nai's first betrayal of the first time, was at the moment Cheng (Oi Ikuki) returned, and began to report to Cheng Nai's betrayal to Cheng Nai with a smile.Seeing this scene, Ichiko believed that Lina's weakness was%sincerity, and what happened later made her more convinced of this.

Saezi and Xiaomei tried to let them separate by revealing Lina's true identity ...

Makoto (Yuki Inoue) still protects his wife even after watching the video of Renai (Naki Shibuya)'s murder. Sasa Tomoko (Sasaki) was shaken after hearing this.Sachiko, who was asked by Cheng to quit her job as a nanny, ambushed Cheng in order to restore Cheng's trust and got the opportunity to talk alone.

Satoko, who avoided the fire, narrowed the distance with Cheng on the grounds of preparing for Renai's surprise party.Then Sachiko sweetly invited Mako to buy things and decided to meet at the flower shop on holidays in the store.However, at this moment, Reina came with caution...!?

In order to find out the past of Makoto (Yuki Inoue), Sasaki (Sasaki) intends to contact Minoru (Orio Tengro).However, the information I received was that Cheng's mother was killed and the prisoner had not been caught.On the other hand, Renai (Natsuki Shibuya), who doubts Satoko, also asks Minor to investigate the origin of Satoko.

At the concert, Rena decided not to be at home for a week, and Sachiko planned to gain sincere trust during this period.Satoko sincerely invited Satoko to have supper together. Satoko gradually shortened the distance with Mako, but Rena added a surveillance camera next to Satoko.

One day, when Mako listened to the piano played by Satoko accidentally, his expression gradually changed.And there was a question flashing through Lina's mind when she looked at her camera...!?

Sasaki (Sasaki) and Komi (Sosaki Yuka) first met in the ward of the burn center where Sasaki was taken to.Like Satoko, the person who has important people was killed by Rena (Natsuki Shibuya) and contacted Rena as the influencer %Kuriya.

Although Renai cares about Satoko and Makoto (played by Yuki Inoue), Shuria said that Renai has nothing.However, when Rena was not at home in the concert, Sachiko and Mako kept monitoring with their cameras, and Sachiko began to notice something.Lina, who wanted to return to her home as soon as possible, started a new crime.

At the same time, Sachiko, who was alone, was thinking about Mako's affairs.Although I planned to take revenge, my love relationship with Cheng revived...