Hoshino Aqua. o(T□T)o

Hoshino Aqua is a young man with short, light-blond hair. He has blue eyes and a rarely changing face, giving him a serious and thoughtful appearance. A six-pointed star appears in his left eye, alternating between white and black. This star disappears at the end of the second season. He has no permanent outfit, but is most often seen wearing Yoto's blue school uniform. He is the son of Hoshino Ai and Kamika Hikaru and the twin brother of Hoshino Ruby. Following the death of his mother, he has become a rather withdrawn person. He uses people to achieve and advance his goals. He appears indifferent, but his soul is constantly torn. He tried to find a career, but after failures, he abandoned his plans. He is tenacious and determined, but also has a tendency to give up on any activity as soon as he discovers his lack of talent. According to Ruby Hoshino, after certain events, he became less emotional and trusting.
She doesn't hesitate to manipulate the feelings of others if she deems it justified. Sometimes, genuine impulses shine through this defense: concern for her sister, respect for the talent of her colleagues.
Aqua has a sister complex: he is very protective of Ruby, and does not want her to become an idol like their mother.

With Akane Kurokawa - The plot follows Aqua and Akane's developing relationship: at first, they play a couple in a project, but then their bond deepens. Aqua maintains a fake relationship with Akane to exploit her talent as a Hoshino impersonator. Aqua and Kana Arima have a friendly relationship, although Kana harbors feelings for Aqua. Aqua and Kana performed together in a show when they were three years old. Years later, they rekindled their friendship in high school. Kana was delighted when Aqua suggested they form an idol group with his sister, Akane. However, when Aqua kissed Akane during filming, Kana was devastated. On the other hand, Aqua finds Kana's personality unpleasant and her behavior rude. Despite Kana's growing feelings, Aqua only sees her as a good friend and is unwilling to form a relationship with her. Akane has blue hair that dries to turquoise, and her eyes are blue-blue. She has fair skin. By nature she is deep, soft, shy, and sometimes talented.

Kana Arima is a major supporting character in the manga and anime Oshi no Ko (Star Child). She has known Aqua and Ruby Hoshino since childhood and was once an acting prodigy, though her popularity has waned over time. She is also the center of the revived idol group B-Komachi. Despite her talent, she began receiving fewer offers due to her difficult personality, forcing her to change her acting style to survive in the industry. However, after reuniting with Aqua and Ruby, joining B-Komachi, and developing a rivalry with Akane Kurokawa, she gradually began to shed her self-imposed limitations. Initially introduced as a self-assured and sharp-tongued young actress, Kana was deeply moved to tears after seeing Aqua Hoshino perform. Since then, she has matured and become much kinder, although her blunt manner still surfaces during moments of intense emotion. She constantly strives to improve. And although the peak of her fame is behind her, becoming an outstanding actress remains her primary goal. Kana is described as a diligent and hardworking woman, empathetic, cheerful, self-confident, and possessing a strong sense of responsibility. At the same time, due to past events, she can sometimes be rude and sarcastic. As mentioned, she continued to hone her acting skills even during periods of unemployment. She prioritizes the quality of the final product above all else, even if it means lowering the bar for her own performance or risking her reputation as an actress. As a child, Kana was often praised for her talent, called a brilliant actress. However, this success went to her head and negatively affected her character: she became arrogant, domineering, and extremely difficult to communicate with.

Ruby is a cheerful idol from the group B-Komachi who always shines on stage. She's known for her warm smile and vibrant energy, but behind this lies a big secret about her family. She's the daughter of legendary idol Ai Hoshino, a fact unknown to the general public that has become her primary motivation for shining in the entertainment world. Losing Ai in a tragic incident in her past left a deep wound, but also strengthened Ruby's resolve to follow the same dream. She is very close to her twin sister, Aqua, though they have different ways of coping with their pasts. In front of fans, Ruby is cheerful and a little flirtatious, relishing the moment her gaze meets someone in the crowd. Their closeness begins with mild curiosity, then gradually develops into a warmer and more personal relationship, while Ruby continues to hide her most private side behind her idol smile. She has warm yellow blonde hair like Aqua, and pink eyes, one of which has a six-pointed white sparkle like Aqua's.

Ai is the deceased mother of Ruby and Aqua Hoshino, a former popular idol in the pre-disbanded group "B Komachi." She had purple hair with sparse pink streaks. Her eyes were starry: purple-pink with white hexagonal sparkles. She died (murdered by a cruel fan (who hated her when one learned she had children) via a package sent by Ruby and Aqua's father, Hikaru Kamiki) when Aqua and Ruby were three years old. On stage, she was a lioness, confident, attractive, and charismatic. In everyday life, she could be naive, careless, a little clumsy, and gullible. Because of her orphanhood, Ai believed her heart was empty and incapable of truly loving others. She often lied, masterfully hiding her true emotions/feelings behind a fake smile and beautiful words. Despite her fears, she sincerely wished happiness for her children—Aquamarine and Ruby—and truly loved them. At first, she didn't think she loved her children because she thought she couldn't love, but when she died of blood loss in Aqua's arms, stroking his head, she was able to say she loved them. (She died because when the doorbell rang, Vi went to answer it, and when she did, there stood this fan in a black hoodie with a knife. He stabbed her in the stomach, and she died of blood loss, leaning against the closed door, hugging Aqua.)