Episode 1

Mother and Children is the first episode of Oshi no Ko anime adaptation.

Synopsis
Goro is devastated when his favorite idol announces that she's taking a break, and he's even more shocked by a new patient who walks into his clinic.

Summary
Goro watching an Idol DVD in a patient's room in a hospital revolving around his favorite idol Ai of B-Komachi until a nurse politely rebukes him over it. The nurse then informs Goro that Ai has gone on hiatus due to poor health. Hearing this devastating news, Goro recalls when he first started out as a doctor in the hospital about a patient named Sarina who changed his life forever.

A flashback involving Goro and Sarina shows that Sarina was a cancer patient obsessed with the Idol group B-Komachi. She tells Goro her favorite singer is Ai and talks about the possibility of being born a celebrity's child if she were to die. Though Goro coldly dismisses the idea of being reborn as a celebrity and claims that Sarina can become an idol when she is discharged. Goro also claims he'd become her fan, causing Sarina to embrace him lovingly and ask him to marry her, but he flatly declines, but states he'll consider it when she becomes sixteen.

In the present, Sarina died at age 12 of anaplastic astrocytoma; if she were alive, she'd be 16, the same age as Ai. However, the nurse continues to believe that Goro is a pedophile, much to Goro's chagrin.

Dodging a question from the nurse, Goro heads to see his next patient, and to his astonishment, it was Ai, who, accompanied by her agent Ichigo, was 20 weeks pregnant. When Goro steps outside to wrap his head around the situation, he overhears Ichigo asking who the father is of Ai's child, which she claims was a secret.

After performing an examination on Ai, it was learned that Ai was pregnant with twins. Ichigo claims that Ai's career as an Idol would be ruined if word got out about her pregnancy, and when Ai asks for Goro's opinion, he states that the final choice lies with her.

Afterward, Goro grabs a drink from the waiting area and overhears two men watching a news story about a marriage between two celebrities who were expecting. One of the men claims that if he were to die then and there, he'd be reborn as the celebrity's child.

On the hospital rooftop, Goro reflects on the self-centered nature of Idol fans. Moments later, Goro is joined by Ai, and they have a heart-to-heart about why she's in the countryside rather than Tokyo, about Sarina, a former patient of his that was a big fan of Ai. They also talk about how Ai decided to keep her unborn children, all while continue being an idol and withholding said information from the public. Ai then explains that lies are the most exquisite form of love. Listening to this resolves Goro to ensure that he safely delivers Ai's children for her.

The following day, Goro explains the process of Ai delivering Ai's babies either by C-section or Sophrology, which concern Ichigo. However, Ai was confident in her health and would deliver her babies without trouble.

On Ai's expected delivery day, Goro walks outside, where an illusive man confronts him about Ai being hospitalized there. When Goro questions the man about where he got his information from and if he's related to Ai, the man rushes off, and Goro pursues him. Goro's pursuit of the man leads him to a cliffside by the mountains, where he's pushed to his death. As Goro's consciousness fades, he recalls what Sarina said about being reborn as the child of a celebrity.

As it turns out, Goro was reborn as one of Ai's twins Aquamarine, aka Aqua. To Aqua's perplexion on why he was reborn with his previous life's memories intact, he, as a former doctor, hopes to figure out how and why. Until he does, Aqua plans on enjoying his life with Ai to the fullest. Aqua's twin sister, Ruby, is also introduced, and as Ai cradles her two children, Ichigo and Miyako visit them. Ichigo announces his plans to have Ai return to the Idol scene; furthermore, Ichigo refuses to allow Ai to bring her children to the studio or any public place.

That night, while Miyako begrudgingly babysits Aqua and Ruby, Aqua turns on the tv to see his mother nearly flub an interview where she reveals she had a "baby". After this, B-Komachi performs one of their songs, and Aqua watches intently while seeing a positive side to his death from a murderous fan of his mother. Immediately, Ruby learns that their mother is on TV and fawns over her performance. It's also revealed that Ruby was another reborn individual after seeing her having a flame war with some fans using their mother's smartphone. Unbeknownst to the two, Ai's stalker, who killed Goro, was visibly upset that she lied to them.

One day, Ai leaves to perform her idol duties again with Ichigo, leaving Miyako in charge of babysitting her twins again. Then, Miyako has a meltdown despite being the president's wife; she's tasked with babysitting. Right as Miyako was taking pictures of Ai's health records, showing that she was pregnant with twins as a way of starting a scandal. Aqua, however, confronts Miyako sitting on top of the coffee table, claiming he's a "Divine Messenger" to stop her. At first, Miyako believed that Aqua talking was some prank, but when Ruby, who also played along with Aqua's fabrication, claims that the gods of entertainment chose Ai. She also claims that Aqua and herself were the ones who bore a monumental destiny, and if she were to ruin it, Miyako would perish. The revelation makes Miyako tearfully remorseful, and Ruby asks that she protect them and keep their ability to speak a secret. Miyako believes it after hearing that a 2nd marriage to a handsome actor isn't out of the question.

After this, Aqua asks Ruby if she was an actress in her previous life, but Ruby denies it, claiming she was raised in an "unusual" environment. Aqua then claims that Ruby may have the talent to be in the entertainment industry, giving Ruby contemplation about her future.

One night, Aqua covers Ruby, who was sleeping on their couch, with a blanket, and calls her Sarina, which makes her wake up. Upon waking up, Ruby walks away and briefly looks at Aqua, considering that he may be Goro from her previous life.

Despite the fervent return of B-Komachi, the group's profits weren't lucrative, which Ai complains about. Miyako then opines on the downsides of being associated with a small talent agency. Hoping to provide her children with a good life and education, Ai vows to do her best to earn more money for her kids. Ai then leaves, and Aqua explains to Ruby about the average pay of Idols and how the profits they make are split between various factors. The two then vent their frustration to Miyako, who explains the life of Idols who go solo and, if they fail, become either waitresses at high-end bars in Roppongi or Minato girls.

Eventually, the twins attend a mini-concert where they watch their mother's group perform. Amid their mother's performance, they unintentionally draw attention to themselves by cheering with the crowd. Their act also went viral with a 2 million viewed video. Ai was also intrigued by it, taking note of a fan's comment about her smile, which Ai claimed she'd use to her advantage.

One year passes, and the twins can walk and talk without secretly needing to do it. Also, during that time, Ai accrued new jobs, and her latest one was a minor part in a TV drama series.

At the scene of the set, Director Taishi leaves an intense impression on the twins due to his appearance. Aqua would later run into Taishi, who threatened if he cried or made a scene there, he'd be kicked out. Panic-stricken, Aqua profusely apologized to him, which shocked Taishi how Aqua's vocabulary was so immense. Taking an interest in Aqua, Taishi offers him his business card, and Aqua claims that instead of him, he'd rather have the job offers go to his mother. Taishi then explains the difficulty of the entertainment industry with three types of actors—the main ones, natural talent, and newcomers. They then watch Ai's performance, and Taishi claims that her acting was average, but notes it at least draws attention.

That evening, Ai and her children watched the show where Ai performed, but were shocked to see that she only appeared in a small scene. Aqua contacted Taishi over this, who explained that the lead actress' agency had Ai's scenes cut back due to her not stealing the limelight with her beautiful looks. Despite this outcome, Taishi claims he'd like his mother to participate in an upcoming film he'll be directing on the condition that Aqua appears in it too.

On the day of the film's first recording, Taishi explains the contrast between a high-budget and a low-budget production to Aqua. Taishi also reveals that the film they're doing that day is low-budget. Despite, Aqua believing his sister is better suited to act in the film, Taishi wanted Aqua to be in it as part of his bargain to allow his mother to be a part of the film.

Later, Ruby has a tantrum for not being able to enjoy Ai's loving embrace since the days of her filming didn't correlate with Aqua's. A little girl, who was also in the room, scolds Ruby for her inappropriate manner and introduces herself as Kana Arima. It's revealed that Kana is a genius actor, and she complains that the twin's mother was an impromptu addition to the film. Before leaving, Kana chastises the twin's mother as a talentless hack who got her role thanks to nepotism.

Afterward, Aqua and Kana play out their roles as "creepy children" who greet the main character at the village entrance where the film's setting takes place. As Aqua cogitates on playing his role, he acts in a way he hopes would impress Taishi. When Taishi calls it a scene, Kana walks away feeling envious and in disbelief, and the leading actress details Aqua's acting sent chills down her spine. Kana then asks Taishi to reshoot the scene; however, he declines, saying it was perfect. In an outburst, Kana proclaims that it wasn't as her acting wasn't up to par with Aqua's.

That afternoon, Taishi and Aqua have a heart-to-heart about Kana's tantrum, communication skills are a big part of acting, and how having a big ego early in life can ruin your future as an actor. Although Taishi had high hopes for him being an actor, Aqua had no intentions of being one.

Late at night, Kana was driven home, reviewing the script vows that Aqua won't get the best of her next time.

Now age three, it's shown that Taishi's film was a hit, and he was nominated for an award. As for Ai, who carried the film, her popularity grew because of it, and she started to become an up-and-coming media personality. Still, Aqua's previous life's corpse has yet to be discovered.

Enrolled in preschool, Aqua asks Ruby about her identity in her previous life. However, Ruby deflects the question with a lie to avoid being looked down upon because she was young when she died.

When their teacher announces it is time for dance class, Ruby runs away in fear and is soon approached by Aqua, who learns that Ruby considers herself a terrible dancer. Ruby then briefly recalls her time as Sarin, having mobility issues.

Eventually, Ruby accompanies her mother in doing some dance practice, where she points out that Ai's choreography is wrong. This earns her mother's praise for remembering something like that. Trying to recreate the proper pose, Ruby falls down, and Ai says that whenever Ruby moves, it's as if she's ready to fall at any time. Ai then tries to cheer her child up, and Ruby recalls being bedridden for the remainder of her previous life. Her only solace was being enamored by watching Ai perform her spectacular dance moves and hoping she could move like her. As Ruby started practicing her dance routine, Aqua secretly watched, noting she had talent as an actress and a dancer.

On a whim, Ai contacted the twin's father asking if he'd like to see their children. Ai trying to reconnect with their father was brought up after she eavesdropped on a conversation between the twins concerning who their father was.

Recent news of Ai's popularity as a tv drama star and idol had increased, which Ichigo had drunkenly relished. B-Komachi was also scheduled to perform at a dome, which was one of Ichigo's dreams. In Ai's internal monologue, she confesses that she's a liar and sometimes can't distinguish whether the emotion she portrays is genuine or not. A brief flashback depicts Ai being first scouted by Ichigo, who conveys her checkered backstory to him. However, Ichigo persuades her to accept his offer, claiming that lying is an essential talent in the idol field.

One day, someone visits the Hoshino residence, and the person holding a bouquet of flowers congratulates Ai and asks if the twins are doing well. He then proceeds to stab Ai in the stomach and then proclaims that he lied to him and her fans. Although wounded, Ai goes on a monologue about dishonesty as an idol and admits that lies are a form of love to her. Ai's confession leaves the man startled and perplexed, and then Ai recognizes him as Ryosuke, someone who frequently attended her "Handshake" events. Panic-stricken, Ryosuke leaves the scene as Aqua contacts an ambulance for his mother. As Ai bled out, she embraced Aqua while lamenting that her scheduled events would soon be canceled. Blocked by the doorway leading into the hallway, Ruby demanded what was happening, and Ai complimented Ruby's performance at her preschool event. Ai then thinks that Ruby will become a popular dancer, and Aqua, a famous actor, while then wondering what her children will be as adults. In her final moments, Ai sincerely tells her children that she loves them and is elated that she did it.

Days after Ai's murder, news of death is announced, and her murderer tried to commit suicide and was pronounced dead at the hospital. Her death drew sympathy from the public. Ruby especially took the public's dark opinions on Ai's death with great disdain, noting how cruel and insensitive it can be.

Time passes by, and Ai's death soon fades from the news, and Ichigo and Miyako adopt the twins. During their mother's funeral, the twins sit in the backseat of a car, and Ruby says that Ai told her she has the talent to become an idol, and Aqua details the dark side to her of that lifestyle. Aqua then realizes that Ryosuke couldn't have killed him in his previous life, nor would he have located Ai's location without an informant. From his deductions, Aqua concludes that the informant is his father and vows to murder him with his own hands.

Approaching Tashi, who was at the funeral, asked that he raise him, leaving him astonished.

Years pass, and the twins are now teenagers, where Aqua's revenge play commences!

In the after-credits scene, Ai videotapes a video of the twin's 1st birthday, where she talks about their future while cradling them as they sleep.