Ruby Hoshino

She looks like sunshine. She sings like an angel. And underneath that idol smile? There's a woman ready to burn down an industry to avenge the people she loved.

Ruby Hoshino is the twin sister of Aquamarine Hoshino and the reborn soul of Sarina, a terminally ill girl who was saved emotionally by Dr. Goro before her death. Now, in her second life as the daughter of the legendary idol Ai Hoshino, Ruby has one dream: to become an idol just like her mother.

But [Oshi no Ko] Season 3 is changing everything.

More Than Just "Aqua's Sister"

For two seasons, Ruby played the supporting role. She was the comic relief, the genki girl chasing stardom while Aqua brooded over conspiracy theories.

That era is over.

Ruby discovers that Goro—her "Sensei" from her past life, the only person who made her feel like living was worth it—was murdered. And she connects the dots: his death, Ai's death, same culprit.

Cue the revenge arc.

The Duality of Ruby

• The Idol: On stage, Ruby is B-Komachi's brightest star. Her performances are electrifying, her smile infectious. She inherited Ai's ability to lie with her eyes—except Ruby's lies are about hiding pain, not love.
• The Avenger: Off stage, Ruby is digging into her family's darkest secrets. Unlike Aqua's cold calculation, Ruby's pursuit is fueled by raw emotion. She doesn't just want answers. She wants blood.

Why Ruby Matters

Aqua's revenge was always clinical. He approached it like a director plotting a scene.

Ruby's revenge is personal. Primal. She's not playing 4D chess—she's going straight through the front door.

And that makes her the most dangerous Hoshino twin of all.