"Rent-A-Girlfriend" centers on Kazuya Kinoshita, a college student who, after being dumped by his girlfriend Mami Nanami, turns to a rental girlfriend service to cope with his loneliness. Through the app, he meets Chizuru Mizuhara, a charming and professional rental girlfriend who initially appears to be the perfect companion. However, Kazuya’s impulsive decision to rent her repeatedly leads to a series of increasingly complicated situations.

Chizuru, despite her polished and accommodating demeanor as a rental girlfriend, harbors her own struggles and aspirations, particularly her dream of becoming an actress. As Kazuya continues to interact with her, he discovers her more genuine and vulnerable side, blurring the lines between their professional relationship and personal feelings. Their dynamic becomes further entangled when Kazuya’s grandmother, who is fond of Chizuru, mistakenly believes they are in a real relationship. To avoid disappointing her, Kazuya and Chizuru agree to maintain the facade, which complicates their lives as they navigate the expectations of family and friends.

The series introduces additional characters who add layers to the narrative. Ruka Sarashina, another rental girlfriend, develops genuine feelings for Kazuya and becomes determined to win his affection, creating tension between her and Chizuru. Sumi Sakurasawa, a shy and introverted rental girlfriend, also enters Kazuya’s life, offering a contrasting personality to the more assertive characters. Meanwhile, Mami, Kazuya’s ex-girlfriend, re-enters the picture, often stirring up drama and questioning Kazuya’s choices.

As the story progresses, Kazuya grapples with his growing feelings for Chizuru while trying to reconcile his insecurities and self-doubt. Chizuru, in turn, struggles to balance her professional obligations with her personal emotions, leading to moments of introspection and growth for both characters. The series explores themes of love, self-worth, and the complexities of human relationships, often blending comedic and dramatic elements to depict the challenges of navigating romance in unconventional circumstances.