Oshi no Ko: Do Ruby and Aqua have a secret sibling? Explained

Created by Aka Akasaka and Mengo Yokoyari, Oshi no Ko follows the lives of Aqua and Ruby Hoshino, twins who were reincarnated from a doctor and his patient and are the children of well-known idol Ai Hoshino. The manga has been serialized in Weekly Young Jump since April 2020 and has an anime adaptation that premiered in April 2023.

One of the most discussed aspects of the series is the possibility of Ruby and Aqua, the two main protagonists, having a secret sibling. This theory has sparked countless debates and speculations among fans eager to uncover the truth behind this mystery.

Disclaimer: This article contains major spoilers from Oshi no Ko manga.

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Oshi no ko: Exploring the identity of Ruby and Aqua's secret sibling

Ruby and Aqua (Image Via Doga Kobo)

One of the mysteries that Oshi no ko manga explores is the identity of the twins’ biological father, Hikaru Kamiki, who was involved in the murders of Ai Hoshino and Gorou Amemiya, the doctor who delivered them. Aqua Hoshino has been looking for his father for years to seek revenge for his mother’s death. However, he soon discovers that he has a half-brother, Taiki Himekawa, who is also an actor and the son of Hikaru Kamiki.

Taiki was conceived when his mother, Airi Himekawa, who was married to Seijuurou Uehara at the time, had an affair with Kamiki. Taiki said that Toshirou Kindaichi adopted him after his parents passed away and raised him ever since after picking him up from an orphanage.

Taiki Himekawa is unaware of his father’s crimes and his connection to Aqua and Ruby. He makes friends with Aqua after seeing him on stage, not realizing that they are half-brothers. He reveals to Aqua that his parents both killed themselves.

How Taiki would respond after discovering the truth about his father and his siblings is still a mystery in the manga. He’ll have to confront the truth about his father’s horrible crimes and his tangled relationships with Aqua and Ruby, so he may be startled and torn. Given that Kamiki is still alive and might attempt to hurt or exploit him for his own ends, he could also be in danger.

Oshi no Ko manga explores the dark side of the entertainment industry and the consequences of secrets and lies. It also demonstrates the surprising ways in which fate may unite individuals. There are still more twists and turns in store for fans of the manga.

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More about Oshi No Ko

The series follows a gynecologist and his patient, reincarnated as twins to a famous Japanese pop idol. They are raised in the entertainment industry and want to learn the truth regarding the identities of their father and the killers of their mother and former selves.

The plot begins with Gorou Amemiya, a gynecologist and fan of Ai Hoshino, a popular idol singer, who becomes pregnant at the age of 16. Gorou delivers her twins, Ruby and Aqua Hoshino, secretly. On the other hand, Gorou is murdered the night of the delivery by an ardent admirer of Ai, who later kills himself.

Gorou is reincarnated as Aqua, Ai’s son, retaining his memories of his previous life. Aqua’s twin sister, Ruby, is also a reincarnation, but she refuses to admit her original identity as one of Gorou’s patients who got him interested in Ai in the first place.

Oshi no Ko depicts the dangerous and dark side of being a fan and an idol. It also demonstrates the twins’ and their mother’s love and fidelity, as well as their struggles with their identities and futures.

Critics and fans have praised the series for its original and captivating story, its surprising and emotional twists, and its realistic and relatable characters. Oshi no Ko is available to read on Manga Plus and Yen Press websites. The anime adaptation can be streamed on HIDIVE.