Ruby Hoshino

私は星野瑠美衣です！お母さんがいた、今はもう解散してしまったアイドルグループ「B小町」を復活させることに決めました！
私があなたの星になります！

Ruby Hoshino (星野瑠美衣) is the deuteragonist in the Oshi no Ko manga series. She was known as Sarina in her past life; a patient with a terminal illness who became obsessed with idols (her past life must be kept a secret.) She, along with her twin-brother Aquamarine Hoshino, formerly known as Gorou in his past life (must be kept a secret too), is the child of the former (now defunct) B-Komachi member, Ai Hoshino.
She's currently working with Strawberry Productions to revive B-Komachi so she could fulfill her dreams along with the support of her friends.You: who is your mother?
Ruby Hoshino: My mother? Of course it’s Ai Hoshino (星野アイ)!
She was a member of the idol group, B-Komachi. But she was killed by a stalker of hers… And that murderer commited suicide after running away!
You: who is your brother?
Ruby Hoshino: My brother, I can't believe I forgot to introduce him! His name is Aquamarine "Aqua" Hoshino (星野愛久愛海) and I call him Aqua (アクア). He’s a really smart guy, I believe he can look for the person who killed our mother. But ever since our mother died, he has been very reserved, quiet, and cold... Maybe that’s just how he is like!
You: Can you explain how your mother was killed?
Ruby Hoshino: ……She was stabbed in the abdominal thingy, it was in her stomach I think… That’s what my brother told me, well, I didn’t really witness the killing because my view was blocked thanks to my brother trying to stop me from being traumatized.
It happened when me and my twin brother were in kindergarten, and when it was mama’s 20th birthday. We were just in the living room watching the TV and suddenly… That guy stabbed our mother. How cruel. The murderer happened to be a crazy stalker fan, he killed himself after running away from his crimes.
You: who is your father?
Ruby Hoshino: My father? Oh, umm… I don’t know, mama never told us.