The opening scene of Rent-A-Girlfriend sets the stage for all the wackiness that eventually plays out: hapless protagonist Kazuya Kinoshita is unceremoniously dumped by his girlfriend Mami Nanami, who cheerfully tells him she's found someone else. While Kazuya responds by renting a girlfriend named Chizuru Mizuhara, an awkward series of events with Kazuya's family and friends forces the two to keep up the lie and pretend they're in a real relationship.
All throughout Season 1, Mami is portrayed as the story's antagonist. It infuriates her not only that Kazuya found a new girlfriend so quickly, but that Chizuru is also beautiful and an upstanding person. Mami on the other hand is self-centered and manipulative, plotting to break up the supposedly in-love couple. But where does this behavior and personality stem from? Could there be more to Mami beneath the surface or is she exactly as shallow as she appears?
The first time Mami sees Kazuya with Chizuru at a restaurant, the two girls chat and Mami reveals a host of secrets from Kazuya's past just to embarrass him. Later during a group trip to the beach, Mami gets Kazuya alone and pretends to slip in the water. Kazuya, for once, does the right thing and catches her -- only for Mami to lean in and kiss him. It's not because she regrets breaking up with him, but she rightly suspects he still has unresolved feelings for her and can manipulate him. More than anything, Mami enjoys being in control. When something surprises her or is beyond her ability to exert that control, she grows upset.
There are even more callous sides to Mami's character. She asks Kazuya to meet her at the hotel near the beach that evening but when he misses it -- due to saving Chizuru from drowning and nearly dying himself in the process -- she doesn't even pretend to express concern or relief that he's okay. When he goes over to apologize for missing their meeting, despite having nothing to apologize for, Mami shuts her car window without a word. Whatever she'd planned to tell him at the hotel, it was not going to be an apology or an honest romantic confession. Most likely, she was going to claim she still had feelings for Kazuya just to watch him squirm even more than he already was.
Despite being driven by selfish and shallow desires, Mami has her moments of introspection. After spotting Kazuya on a "date" with Chizuru's rental girlfriend colleague Sumi Sakurasawa, Mami returns home and questions what it is about Kazuya that attracts these beautiful girls. She even wonders if there's something she missed during their relationship and whether she regrets ending it so soon. Of course, she goes right back to her manipulative ways when she discovers the truth about Kazuya's involvement with rental girlfriends.
Though she has her circle of friends and a number of would-be romantic pursuers, Mami is pictured alone quite often. In a series where many characters are constantly putting on an act -- either for their job or to hide damaging secrets -- they reveal multiple layers to their personalities. But what's behind Mami's act, or is it an act at all? What's beneath the attempts to seem sweet and oblivious at times, while warning Chizuru in the finale that she's harming rather than helping Kazuya?
When looking at all the evidence of Season 1, there are no deeper layers or hints of a redeeming personality. She's simply the shallow ex-girlfriend who manipulates those around her for her own selfish, twisted pleasures. That said, Season 2 could change this. Aside from a brother shown in one scene, almost nothing is known about Mami's backstory, her home life or her goals and dreams. The series continues to build more layers to Chizuru's story while Ruka, Kazuya and Sumi are all trying to better themselves and their lives. Should Mami ever show an effort to do the same, it could drastically expand her character while affecting the series' primary dynamic between Kazuya and Chizuru.