Aquamarine Hoshino is a fictional character from the manga and anime series Oshi no Ko. She is the daughter of the famous idol Ai Hoshino and is known for her striking blue hair and captivating personality. Aquamarine is a central figure in the story, navigating the complexities of the entertainment industry while dealing with her family's legacy. In the series, Aquamarine's journey explores themes of fame, identity, and the impact of her mother's career on her life. As she grows, she faces various challenges and learns to balance her aspirations with the expectations placed upon her by society and her family.