WARNING: The following contains spoilers for Rent-A-Girlfriend Season 1, Episode 7, "Provisional Girlfriend and Girlfriend," streaming now on Crunchyroll.
Kazuya Kinoshita should be rejoicing. A cute girl who expresses genuine feelings for him has taken it upon herself to ask him out. Except... it's not the girl he has feelings for, and she's blackmailing him by threatening to expose his rental girlfriend relationship with Chizuru. After openly admitting to being Shun's rented girlfriend, Ruka incessantly begs Kazuya to date her in a real relationship. Though Ruka is extremely possessive and grows jealous easily, it's clear there is more going on with her than meets the eye.
After the completely fake double date of Kazuya, Chizuru, Shun and Ruka ends, a paranoid Kazuya rushes after Ruka, who takes his action as a guilty admission that Chizuru is indeed a rental girlfriend. After another accidental perverted moment with Ruka, Kazuya begs her not to tell Shun the truth. He explains how he and Chizuru first met, and why they've been forced to keep up the true couple act. Ruka is struck by his sincerity and how he even puts Chizuru's wellbeing ahead of his own.
Insecurity is the overriding theme of this episode, with all four of the key players wrestling with their feelings while trying desperately to keep important secrets from being revealed. As Kazuya works to keep the truth about him and Chizuru hidden, poor Shun has his own secret brutally exposed. Ruka, as suspected, is also a rental girlfriend. She arrives at the college campus looking for Kazuya, just as he's supposed to meet with Shun. The two run into an empty classroom where Ruka tells Kazuya her own secret, then suddenly asks for a hug.
It's unclear why, but Ruka measures her romantic feelings via her heart rate, or BPM. Her goal is to find someone who makes her BPM reach 90 or higher when they touch her, which Kazuya does. Shun discovers them hiding together, where Ruka apologizes and thanks him for renting her. It's the most unprofessional action she could take, openly exposing her client's sensitive secret, but she seems to be working as a rental girlfriend to fulfill a more personal agenda. Poor Shun is humiliated after being exposed right in front of Kazuya, and after leaving the room in a daze isn't seen again in the episode. A still-confused Kazuya is updating Chizuru outside her apartment when who should show up outside? Ruka.
Continually surprised at how close Kazuya and Chizuru are (including a few misconceptions) despite not being in a relationship, Ruka promises to keep their secret -- but only if Kazuya goes out with Ruka for real. Despite his repeated resistance, she grows insistent, even sinking to the ground crying. It's not clear why she's so intent on dating him, but her feelings seem to be sincere and there is likely more to her personal situation than is seen here. Ruka believes that if Kazuya treats a rental girlfriend so well, surely he'll treat a real girlfriend even better. Of course, she only accounts for the most flattering parts of Kazuya's story: saving a girl's life, wanting to protect his buddy's feelings, etc.
With humor and wacky shenanigans being so constant throughout the show so far, one would expect a girl suddenly obsessing over Kazuya to be comedic, yet the whole situation comes off more serious in its tone. Why does Ruka, a high school girl, work as a rental girlfriend? And if she really does like him, what makes her desperate enough to resort to blackmail to form a real relationship? Naturally, Kazuya doesn't want to date Ruka for two reasons: it would surely damage his friendship with Shun, and Kazuya's true feelings are for Chizuru.
Which makes it notable that Chizuru advises him to date Ruka -- because Chizuru herself needs to keep her job a secret at all costs. She's been clear all along that she can't have anyone on-campus finding out her secret, but here she's more adamant that her grandmother, in particular, cannot find out. It's the first time Chizuru makes a point of putting her own desire first, even if it places Kazuya in a highly uncomfortable position. After initially being against the idea, Chizuru rationalizes that a real relationship could be a good experience for him.
But with such an insecure girl as Ruka -- who is proving to be just as impulsive as he is -- the situation could take just about any unexpected turn very quickly. And as the Rent-A-Girlfriend train has shown all season, it only continues speeding up as it charges along.