【Oshi no Ko】Hoshino Ruby Zodiac Sign Analysis! Revealed from Birthstones: Is She a Passionate Leo or a Gentle Cancer?

Preface: The Personality Code of a Shining New Star

In the super popular anime "Oshi no Ko," Hoshino Ruby (Hoshino Rubii) has become a new generation star who inherits the radiance of her mother Hoshino Ai, with her sun-like dazzling energy and never-give-up idol dream. Fans are curious about everything about her, and "zodiac signs," as an interesting way to explore character personalities, have naturally become a hot topic of discussion. So, what is the zodiac sign of this girl who is determined to shine on stage?

Official Silence: An Unsolved Mystery

First, it must be clear that as of now, the original creators of "Oshi no Ko," Aka Akasaka and Mengo Yokoyari, have not officially announced Hoshino Ruby's specific birth date in any official materials, manga, or interviews. Therefore, her official zodiac sign is unknown. This is the same as her mother Hoshino Ai, whose exact birthday has also not been given officially. This might be a deliberate arrangement by the author, hoping readers focus on the characters' growth trajectories and inner worlds rather than predetermined labels given by zodiac signs.

The Biggest Clue: The "Birthstone" Theory Hidden in the Names

Although there is no official answer, fans have proposed a very convincing theory based on their keen observation - the "Birthstone Theory." The core of this theory lies in the names of the Hoshino siblings.

• Hoshino Ruby: "Ruby" is the birthstone for July.
• Hoshino Aquamarine: "Aquamarine" is the birthstone for March.

The author named the twins after corresponding gemstones, very likely hinting at their birth months. This clever setting also echoes their previous identities (Sarina and Gorou). If this theory holds, then Hoshino Ruby's birthday falls in July. And the zodiac signs for July span Cancer and Leo.