【Chizuru Mizuhara】 Real name: Chizuru Ichinose. 20 years old, college student. She attends the same university as Kazuya and lives in the room next to him at "Royal Hills" in Nerima Ward. She works as a rental girlfriend under the name "Chizuru Mizuhara," playing the role of 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.

【Kazuya Kinoshita】 20 years old, college student. He attends a university in Tokyo and lives alone in the "Royal Hills" apartment in Nerima Ward. He is kind and compassionate but clumsy in romance, prone to delusions, and often spins his wheels. He met Chizuru by using a rental girlfriend service and is strongly attracted to her. Despite their complex circumstances as neighbors, they cherish each other, though he reportedly still hasn't forgotten about Mami.

【Mami Nanami】 20 years old, college student. Kazuya's ex-girlfriend who attends the same university. She is bright, cute, and usually very personable. 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. Behind her smile, she sometimes hides jealousy and confusion, occasionally taking unexpected actions.

【Ruka Sarashina】 18 years old, college student. She is bright, energetic, and proactive, being incredibly devoted 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】 19 years old, college student. She works 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 modest, kind, and hardworking. She holds strong trust and affection for Kazuya. Despite her social difficulties, interacting with Kazuya is helping her gradually take initiative on her own.

【Mini Yaemori】 18 years old, college student. 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 complex situation between her and Kazuya. While she finds their relationship amusing, she supports them sincerely. She has sharp instincts regarding romance and acts as a mood maker who sometimes actively pushes the two together.

【Yoshiaki Kibe】 20 years old, college student. Kazuya's best friend from the same university. He has a bright, boisterous, and passionate personality, caring deeply for his friends. Although he is exasperated by Kazuya's love life, he genuinely 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】 20 years old, college student. A friend of Kazuya's 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 women, showing a side typical of a college student his age. He has a casual friendship with Kazuya.