Oshi no Ko Volume 13 Unveils Aqua and Ruby's Past Life Identities as Goro and Sarina

From the very first volume of Oshi no Ko, readers have known one of the manga’s most pivotal plot twists: Aqua and Ruby Hoshino are the reincarnated souls of Dr. Goro Amamiya and his teenage terminal patient, Sarina Tendouji. While the siblings share this secret, neither knows the other’s true identity.

With the release of Volume 13, that long-awaited reveal finally unfolds. Creators Aka Akasaka and Mengo Yokoyari deliver the emotional payoff with precision, though some shifts in character dynamics may feel unexpected to fans.

Editor’s Note: Volume 13 Spoilers Ahead

The second half of Oshi no Ko has seen the relationship between Aqua and Ruby deteriorate, driven largely by Aqua’s obsession with avenging their mother Ai’s death. Ruby, too, undergoes a transformation, partly due to learning of Goro’s death—the doctor who once treated her when she was Sarina. Volume 13 picks up in the aftermath of Ruby’s emotional collapse, as she grapples with grief, career pressure, and the realization that everyone she loves ends up unhappy or dead.

It’s then that Aqua—now Goro—steps in, witnessing her despair and her heartbreaking wish that she had never been given a second chance at life.

The Revelation: How Aqua and Ruby’s Past Lives Connect

The reveal of Aqua and Ruby’s past lives as Goro and Sarina is executed with remarkable care. The story delves into Sarina’s tragic past, where her parents abandoned her due to her severe illness, leaving her in the hospital’s care without a single visit. Goro, drawn to her loneliness, became a constant presence in her life, bonding over shared interests like B Komachi, Ai’s dreams of stardom, and Sarina’s own aspirations to become a star.

A keychain from their past lives plays a crucial role in Ruby’s realization of Aqua’s true identity. The emotional weight of this moment is amplified by how it reshapes the narrative moving forward.

How the Reveal Transforms the Story

Prior to Volume 13, Aqua was primarily driven by vengeance, while Ruby’s descent into darkness had only recently begun to take shape. Aqua’s response to Ruby’s breakdown marks a turning point. He reminds her of who she was and what she truly wanted—to become a star. This moment flips a switch, steering Ruby toward a new path, reigniting her purpose and hope for the future.

The impact of this revelation extends beyond the twins’ relationship, setting the stage for a dramatic shift in the story’s trajectory. Fans can expect further emotional and narrative developments as Oshi no Ko continues to unfold.