This drama is set on the stage of a third-grade high school class where 18-year-olds become adults and can get married without parental consent. It depicts first love, pregnancy, marriage, and infidelity, and the unheard-of suspense of school infidelity.Cheating with classmates [high school student cheating], cheating with guardians [PTA cheating], and even forbidden [teacher and student cheating]... Moreover, this kind of intertwined thoughts is connected to a certain incident.

Because Uemura Aoi (Riko) was tired of her parents who argued all day long, she went to live in seclusion at her grandmother's house during the summer vacation of her third year of junior high school.She met a young man of the same age, Tachibana Iori (Kazuto Sadai), in a small planetarium in the town, and fell in love for the first time.Ao decided to confess to Iori before the summer vacation ended, but because he “ missed ”, he thought he was dumped. From then on, the two never saw each other again.

Three years later.Ao, who became a third-year high school student, took the opportunity of his parents' divorce to transfer to his mother Haruka's alma mater (Ryoko Kuninaka).This is an elite school with internal admission to college.In the classroom of Class C of the third year, he met Iori again like fate——.

Ao avoids Iori because of embarrassment, and at the same time, she is invited to work part-time by her classmate Sasaki Masuzu (Tanaka Mihisa).In order to help the family, Aang followed Zhen Ling, but found out that it was her father's job.When she felt in danger and wanted to run away, Iori stepped in to help her.In order to resolve the misunderstanding from three years ago, Yi Ribbing took Cang to the night school.There, Iori shows Ao something...!? Ao and Iori's first love is rekindled.However, classmate Takanashi Kotone (Akita Shiori) who holds a certain secret hinders their love.

On the other hand, Haruka, as a guardian, reunites with his former lover Tachibana Yutaka (Takezai Terunosuke) and his friend Tachibana Kyoko (Sakai Miki).Haruka also rekindled the love she was supposed to let go of.

First love is rekindled and begins to take action. The incest between high school students and their guardians begins. The unheard-of suspense of campus incest begins!!

Kotone (Shiori Akita) showed B-ultrasound photos to Iori (Kazuto Sadairo). Iori felt very complicated. Seeing Kotone's sad look, he finally signed the marriage application.Carrying a secret that cannot be told to his parents or anyone else, Iori wanted to cancel the date with Ao, but the date with Ao was what he was looking forward to from the bottom of his heart, and he couldn't express it, so the date came.

On the other hand, Haruka (Ryoko Kuninaka) is invited by Kyoko (Miki Sakai) to have tea at Tachibana's house.There is also her former lover and now Kyoko's husband - Yutaka (Takezai Terunosuke).The three people seemed to be discussing the child's problems calmly, but in fact...! ?

At this time, Ao and Iori were enjoying their long-awaited date and feeling happy.Facing Ao who looked happy, Iori struggled with when to tell him that he was going to get married.At this time, a person appeared in front of the two of them——! ?

Ao (Riko) was forced to become a witness to the marriage, suppressing her inner pain and trying to bless Iori (Kazuto Sadairo) as a friend.Faced with such Ao, Kotone (Akita Shiori) quickly started to attack Iori as his wife.Seeing Ao's painful look, Kanata (Yutarou) called Iori out and questioned him about Ao's crying a few days ago, and asked about the true relationship between the two of them.

On the other hand, Haruka (Ryoko Kuninaka) went to Tachibana General Hospital to treat insomnia. The person in charge was Yutaka (Terunosuke Takesai).During the diagnosis and treatment process, Feng revealed his regret over breaking up with Haruka——!?

Iori, who was hit hard by Sudo, had to confess everything.The truth is revealed about Iori and Kotone’s secrets.The truth about why the two dated and how they were involved in this matter gradually emerged——!

Ao (Riko), who was shaken by Iori's (Kazuto Sakadai) sudden confession, thought it was too late, so she pushed Iori away and left.Ao returned home in a distraught mood, angry at her mother Haruka (played by Ryoko Kuninaka) who was conducting divorce mediation, and locked herself in the room.Although Haruka was worried about Cang, her chest began to hurt...

the next day.Ao started to avoid Iori and went on a date with Kanata.Kudo tries to cheer up Cang, and Cang's heart is healed.But, just then, the school called.Mother fell...!

Haruka was rushed to Tachibana General Hospital.Ao rushed to the scene and learned about the unpredictable situation from Yutaka (Takezai Terunosuke)!?

In the early morning classroom, Ao (Riko) and Iori (Kazuto Sadai) kissed.Iori decided to give up her marriage to Kotone (Akita Shiori) for Ao, and told Kotone that she had something to talk about after school.

On the other hand, Yutaka (Terunosuke Takesai) visits Haruka (Ryoko Kuninaka) who successfully completed the surgery.Because of what happened last night, the two got closer again, recalling the past when they were dating, and Haruka also expressed his hidden thoughts.At this time, Kyoko (Miki Sakai) also came to visit——!?

At the same time, Iori came to Kotone's house and resolutely proposed to terminate the engagement.But after hearing the sound of these words, he took an unexpected action——!?Kotone's growth experience and the reason for her obsession with Iori will be revealed...!

Because Kotone (Akita Shiori) took the initiative to expose the news of her marriage, Class C in the third year was in an uproar.While Iori (Kazuto Sadai) and Kotone were called for questioning by the school, Kyoko (Miki Sakai) and Yutaka (Takezai Terunosuke) also came to the school, and the matter gradually evolved into a game in which even the parents were involved.Into the commotion.Kyoko wanted to talk to Kotone alone, so she took her out.Kyoko tries to convince Kotone to give up getting married and having children, but Kotone is one step ahead...!

On the other hand, Ao (Riko) and Kanata (Yutaro) were shaken, and Ma Suzu (Mihisa Tanaka) found them, and she asked them about their marriage.When she learned that Ma Suzu had only recently discovered that she was pregnant, she smiled meaningfully...!

At the same time, the relationship between Haruka (Ryoko Kuninaka) and Yutaka who was hospitalized quickly became closer, and Ao and Iori couldn't suppress their longing for each other...!

Being questioned by Souta (Yutarou) about cheating, Iori (Kazuto Sadai) tried to deal with it, but Souta's doubts did not dissipate.At this time, the class began planning a wedding celebration.Thinking that this embarrassing situation must be ended as soon as possible, Iori decided to go home, but found that the Tachibana family received a visit from Kotone (Akita Shiori)...!?

Meanwhile, Yutaka (Terunosuke Takesai) goes to visit Haruka (Ryoko Kuninaka) who is about to be discharged from the hospital.Although the two have always kept a distance and never crossed that line, Yutaka seems unable to contain his longing for Haruka.At this moment, Ao (Riko) comes to pick Haruka out of the hospital...!?

On the other hand, since the school approved the marriage of high school students, Ma Suzu (Mihisa Tanaka) also began to force the marriage from her class teacher, Mr. Nakano (Yoshihiko Hosoda) -!?

In order to promote divorce mediation, Iori (Kazuto Sadai) began to take action.However, at the same time, Kyoko (Miki Sakai) learned from Kanata (Yutaro) that Iori had cheated on her.Knowing that her son's cheating partner turned out to be Haruka's (Ryoko Kuninaka) daughter, Kyoko felt that it was a trick of fate, so she forced Ao (Riko) to talk to her about the matter.

At this time, Haruka came for a checkup after being discharged from the hospital.Although Yutaka (Takezai Terunosuke) invites her to a dinner to celebrate her recovery, Haruka decides to avoid any further intimacy with Yutaka, considering Kyoko's feelings.

On the other hand, Masuzu (Mihisa Tanaka) was caught by Kotone (Shiori Akita) about her extramarital affair with Mr. Nakano (Yoshihiko Hosoda).Under the threat of Kotone, Ma Suzu had to go to see a mysterious figure - what on earth is going on?