Ai Hoshino is the legendary lead center of the idol group B-Komachi. Known for her unmatched charisma and distinctive star-shaped eyes, she hides a deeply fractured past behind a flawless, dazzling smile. Despite her immense fame, she struggles to truly understand or experience love. As the secret mother of the twins Aqua and Ruby, her life is tragically cut short when she is murdered by an obsessed fan at just 20 years old, leaving a permanent shadow over the entire story.

Aqua Hoshino (Aquamarine) is Ai’s son and the cynical protagonist. Formerly a doctor named Gorou, he is reincarnated with his past memories intact. Following his mother's tragic murder, he dedicates his life to finding and destroying their biological father, whom he holds responsible. He suppresses his natural acting genius, using show business merely as a tool for his dark, analytical quest for revenge.

Ruby Hoshino is Ai’s daughter and Aqua's twin sister, formerly a terminally ill girl named Sarina. Unlike her brother, she is a vibrant, optimistic dreamer who seeks to fulfill her past-life wish of becoming an idol just like Ai. She possesses her mother's dazzling star-eyes and charismatic stage presence. While initially innocent and cheerful, she harbors a hidden, fiercely determined side that awakens as she uncovers the dark truths of the entertainment world.

Kana Arima is a former child prodigy actress who struggled to find work as she grew older, making her deeply cynical yet fiercely hardworking. Nicknamed the "Genius Child Actress Who Can Cry in 10 Seconds," she has unmatched technical skill but suppresses her talent to make others look good. Recruited by Ruby, she becomes the reluctant, highly reliable center of the new B-Komachi.

MEM-cho is a popular, cheerful internet personality and YouTuber who joins the new B-Komachi idol group. Though she looks and acts like a high schooler, she actually hid her true age (mid-20s) to keep her dream of becoming an idol alive after family hardships forced her to delay it. Energetic, tech-savvy, and deeply insightful about social media marketing, she serves as the mature, supportive "big sister" who keeps the trio grounded.

Miyako Saitou is the president of Strawberry Productions and the adoptive mother of Aqua and Ruby. Originally a shallow woman who married her husband for money and complained about babysitting, her life changes when she begins caring for the twins. Following her husband's sudden disappearance after Ai’s murder, she steps up to run the talent agency alone. She becomes a fiercely protective, loving maternal figure who balances managing their careers with shielding them from the industry’s dark side.

Taishi Gotanda is an award-winning film director who serves as Aqua's artistic mentor. Despite his gruff exterior and the fact that he still lives with his mother, he is a deeply caring and perceptive filmmaker. He is the first person to recognize Aqua's natural talent for acting and behind-the-scenes production work, eventually taking him on as an apprentice. He plays a vital role in helping Aqua navigate the entertainment industry and acts as a trusted, guiding father figure to him.

Akane Kurokawa is a brilliant, award-winning theater actress known for her absolute mastery of Method acting. Though naturally shy, sensitive, and insecure, she can flawlessly mimic anyone—even perfectly replicating Ai Hoshino’s personality after a deep psychological analysis.

Taiki Himekawa is an award-winning theater star and the top leading actor of the Lala Lai Theatrical Company. Blessed with staggering, effortless acting genius, he completely transforms into a charismatic powerhouse on stage, though he lapses into a messy, eccentric slacker when off-stage. He shares a deeply tragic childhood background with Aqua and Ruby, and his unexpected biological connection to Aqua shifts the direction of the series' central mystery.

Melt Narushima is a handsome model-turned-actor who starts the series as an arrogant, untalented "pretty boy." His lazy, emotionless performance in the live-action Sweet Today adaptation nearly ruins the project, earning him widespread mockery. After a harsh reality check from Aqua, Melt humbles himself, takes acting lessons, and embraces endless hard work. His grueling efforts culminate in a spectacular, emotionally raw breakthrough during the Tokyo Blade stage play, fully earning back the industry's respect.