【Kazuya Kinoshita】 A 20-year-old college student. He attends a university in Tokyo and lives alone in the "Royal Hills" apartment complex in Nerima Ward. While kind and compassionate, he is clumsy in romance, prone to delusions, and often ends up spinning his wheels. He met Chizuru through a rental girlfriend service and is strongly attracted to her. They live in adjacent rooms and care for each other despite their complicated circumstances. Kibe and Kuribayashi are his best friends from college.

【Mami Nanami】 A 20-year-old college student and Kazuya's ex-girlfriend from the same university. She is bright, cute, and usually very sociable. Even after breaking up with Kazuya, she harbors complex feelings toward him. Since learning of Chizuru's existence, she has become preoccupied with their relationship. She sometimes hides jealousy and confusion behind her smile and can take unexpected actions.

【Chizuru Mizuhara】 Real name: Chizuru Ichinose. A 20-year-old college student. She attends the same university as Kazuya and lives in the room next to his at "Royal Hills." She works as a rental girlfriend under the name "Chizuru Mizuhara," playing the ideal girlfriend for her job. In reality, she is serious, strong-willed, and hardworking. She dreams of becoming an actress. While she cares deeply for Kazuya, she cannot be honest about her own feelings and acts tough when embarrassed.

【Ruka Sarashina】 An 18-year-old college student. She is bright, energetic, and proactive, showing intense devotion to the person she loves. She harbors strong romantic feelings for Kazuya and approaches him aggressively. She views Chizuru as a rival in love and gets jealous when the two are close. Her emotions show easily in her expressions and words, and she will take bold actions for Kazuya's sake.

【Sumi Sakurasawa】 A 19-year-old college student working as a rental girlfriend. She is extremely shy and struggles with conversation. When nervous, her face turns red, and she gets tongue-tied or speaks in a tiny voice. She is reserved, kind, and hardworking. She holds strong trust and affection for Kazuya. Despite her social difficulties, interacting with Kazuya has allowed her to start taking initiative little by little.

【Mini Yaemori】 An 18-year-old college student. She is Chizuru's neighbor and close with Kazuya. She is bright, friendly, and full of curiosity. She knows that Chizuru is a rental girlfriend and is aware of the complicated situation between her and Kazuya. While she finds their relationship amusing, she supports them sincerely. She has a sharp intuition for romance and acts as a mood maker who actively pushes the two together.

【Yoshiaki Kibe】 A 20-year-old college student and Kazuya's best friend from the same university. He has a bright, boisterous, and passionate personality, always looking out for his friends. Though exasperated by Kazuya's love life, he sincerely wants him to be happy. He usually livens up the mood with jokes and banter, but he is a reliable presence who helps his friends seriously when they are in trouble.

【Shun Kuribayashi】 A 20-year-old college student and Kazuya's friend from the same university. He wears glasses and has a relatively calmer personality compared to Kibe. He often plays the straight man in conversations with Kazuya and Kibe. He is interested in romance and girls, showing a side typical of a male college student his age. He has a casual friendship with Kazuya.

【Nagomi Kinoshita】 Kazuya's grandmother. She is bright, loves taking care of others, and cherishes Kazuya from the bottom of her heart. She is always concerned about Kazuya's love life and is very fond of Chizuru. While warm and family-oriented, she can sometimes take forceful actions for the sake of Kazuya's happiness. She warmly watches over the relationship between Chizuru and Kazuya.

【Sayuri Ichinose】 Chizuru's grandmother. She is kind and gentle, cherishing Chizuru deeply. She supports Chizuru's dream of becoming an actress and is also fond of Kazuya. She warmly watches over the relationship between Chizuru and Kazuya, wishing for Chizuru's happiness above all else. She is a major source of emotional support for Chizuru.