Many of the exaggerated facial expressions seen throughout the series, whether it's Kazuya's countless Oh, Crap! moments, Chizuru going into Cat Mode or getting beady-eyed, Nagomi going into Tears of Joy whenever she sees Chizuru, Ruka's bow becoming devil horns when she's mad, or Sumi whenever she gets too nervous.
In most series, the hero experiencing a Love Epiphany would come off as a genuinely heartwarming moment. Here, Kazuya's Love Epiphany happens while he's masturbating to pictures of his ex in a swimsuit, making it both squicky and hilarious when it comes to timing. No wonder Kazuya's determined not to tell Chizuru about it.
Nagomi, the matriarch of the Kinoshita family, is a woman who ran her family business after her husband's death, successfully got out of debt, and commands respect from her son, daughter-in-law and grandson. She's also a woman who gets so excited over her grandson seemingly getting a girlfriend that she drops everything to bring her friends over and enjoys playing gacha games on her phone (annoying her nurses in the process), among other things. It really goes to show that people aren't always as they seem in this series.
Kazuya lets his Christmas gift from Chizuru go to his head, only to very quickly get disappointed when he sees a message board full of people posting about getting gifts from Chizuru, and for Chizuru to point out that her agency expects her to get gifts for her clients.
Ruka asks if Kazuya plans on renting Chizuru well into their old age. Cue an Imagine Spot in which Chizuru, whose hair has gone gray, informs Kazuya that the fee has increased by 1,000 yen, and a bald Kazuya says that it's worth it.
After being introduced to Ruka, Nagomi takes Kazuya out back and smacks him in rapid succession over at the thought of him cheating on Chizuru with another girl.
When Ruka gets a job at the same karaoke bar where Kazuya works, he blocks her from hugging him with a large metal pan. Ruka claims harassment and demands that their boss reduce his pay, and he actually considers it.
Kazuya worries that Kuri's bitterness over his experience with Ruka, as well as a job managing an orchard out in the countryside, will make him a bachelor into old age. Cue an Imagine Spot of Kuri tweeting about how he's worked on the orchards for the past 40 years, and it ends with him.
During the conversation in which Kazuya apologizes to Kuri, he and Kazuya get into an argument about their respective rental girlfriends' body parts.
When Kazuya takes Sumi out bowling, even though she gets her fingers stuck in the ball and falls down, they're both too embarrassed by the ensuing Panty Shot that neither of them realize she got a strike.
Kazuya's pet fish constantly gets on his owner's ass for not feeding him, not adjusting the water temperature, for losing his grip on reality and his self-awareness. Out of all of the characters in the cast, it's the pet fish who probably serves as the Audience Surrogate the most.
After Kazuya's father punches him for supposedly borrowing money from Chizuru, Kazuya furiously rages outside his apartment, complaining about his father jumping to conclusions. The text box points out that Kazuya does the same thing himself.
When Chizuru's at the hospital visiting her grandmother and finds out that Ruka is making things difficult at Kazuya's joint birthday party, she nervously tries getting Sayuri's permission to go. Sayuri suddenly gets up, glares at Chizuru and goes all What the Hell, Hero? on her granddaughter for not being with Kazuya. Later on, Sayuri embarrasses Chizuru by telling Kazuya and Nagomi that she actually really wanted to go, which surprises and excites Kazuya, earning him a Death Glare from Chizuru.
The morning after the "cheer up" date, Kazuya is so trapped in thought wondering if he helped Chizuru or not, only to suddenly find Mini sitting next to him in the same pose. He freaks out wondering why she's there, and she tells him that his door was open and even rang the bell.
The one-shot Kanojo, Tenseishimasu has Kazuya and Chizuru being "isekai'd" into another world, and he does battle with a slime that resembles his pet fish. Even though Kazuya cuts it in half as it attacks, one half flies straight into Chizuru's face and ends up melting her clothes. Getting a little too into it, Kazuya snaps over the slime's attack on Chizuru's dignity and she pulls out a random shield to cover herself.
Rent-A-(Really Shy!)-Girlfriend
In Chapter 4 of Sumi's spinoff, once she realizes that putting Ruka's pouch in her pocket makes it look like she had stolen it, she freaks out and wails her arms all over the place. After it falls out, Sumi looks her date in the eyes and gets him notice it so he can return it to Ruka. Because of the look she gave him, he gives her a five star rating because he thought he had seen the face of a goddess, something she doesn't recall happening at all.
In Chapter 7, when Sumi passes out after stressing out how her first practice date with Kazuya will go, her dog simply walks up to her and falls asleep next to her. The next morning, Sumi rushes out and ends up arriving early, and tries to kill time by reading the rental girlfriend handbook. She reads the entire thing in five minutes. There are also actually three guys at the rendezvous point, and she freaks out after mistaking a random person as Kazuya.
Chapter 11 revolves around Sumi doing a photoshoot for her agency, and because she becomes so stone-faced and stiff in front of the camera, the entire chapter becomes one large Shout-Out to Minecraft.
