Aqua Hoshino (full name Aquamarine)

With Akane Kurokawa – The plot follows Aqua and Akane as they develop a relationship: at first, they play a couple in a project, but their bond deepens. Aqua maintains a fake relationship with Akane to exploit her talent for impersonating Hoshino. Aqua and Kana Arima are friendly, though 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 pursue a relationship with her.

He possesses tenacity and determination, but also has a tendency to give up on any endeavor as soon as he discovers a lack of talent. According to Ruby Hoshino, after certain events, the boy 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.

As Goro, he worked as a doctor in the gynecology department. Four years before the manga's events, he met a 12-year-old girl, Sarina. She changed his life, but sadly died of anaplastic astrocytoma. It was thanks to her that Goro became a fan of Ai.

One day, a 16-year-old pregnant girl comes to see him with her guardian. This girl turns out to be his idol, Hoshino Ai. At first, Goro was confused, but after a conversation with Ai on the rooftop, he began to help her with everything.

On the day of Ai's birth, Goro encounters her stalker and, hoping to stop him, pursues him. Ultimately, the stalker kills Goro. In his final moments, he recalls something Sarina once said: "Have you ever wondered what it would be like if you were born the child of a celebrity?"

It seemed like the end had come, but upon opening his eyes again, he realized he had been reincarnated as Hoshino Ai's child. His new name was Hoshino Aquamarine. He had a twin sister, Hoshino Ruby.

At the age of three, Aqua starred in a film with Ai.

A few years later, Aqua quit acting because he felt he wasn't skilled enough. Instead, he took a part-time job behind the scenes. A few years later, after enrolling in the general education program at Yoto High School, he met Kana Arima, who invited him to star in a film. Although he hesitated, Aqua accepted for his own personal reasons. Ironically, he played the role of the main character's stalker, threatening her life. His performance on set was flawless, leading director Kaburagi to offer him a role on the reality dating show "My Love with the Stars." Aquamarine accepted.

Since his mother's death, he's become a rather withdrawn person. He uses people to achieve and advance his goals. He appears indifferent, but inside, he's constantly raging.

He tried to find things to do, but he usually gave up after failures.

Uses people to achieve and bring closer the goal.

He is not charmed by compliments. He tried to find a job for himself, but after failures, he abandoned his plans.

Son of Hoshino Ai and Kamiki Hikaru, twin brother of Hoshino Ruby.

Hoshino Aquamarine 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. In his left eye, he has a six-pointed star that alternates between white and black. At the end of the second season, this star disappears. He has no permanent outfit, but is most often seen wearing Yōto's blue school uniform.