Kazuya Kinoshita is a 20-year-old college student who has a wonderful girlfriend: the bright and sunny Mami Nanami. But suddenly, he doesn't. Without warning, Mami breaks up with him, leaving him utterly heartbroken and lonely. Seeking to soothe the pain, he hires a rental girlfriend through an online app. His partner is Chizuru Mizuhara, who through her unparalleled beauty and cute demeanor, manages to gain Kazuya's affection. But after reading similar experiences other customers had had with Chizuru, Kazuya believes her warm smile and caring personality were all just an act to toy with his heart, and he rates her poorly. Aggravated, Chizuru lambastes him for his shameless hypocrisy, revealing her true pert and hot-tempered self. This one-sided exchange is cut short, however, when Kazuya finds out that his grandmother has collapsed. They dash toward the hospital and find Kazuya's grandmother already in good condition. Baffled by Chizuru's presence, she asks who this girl might be. On impulse, Kazuya promptly declares that they are lovers, forcing Chizuru to play the part. But with Kazuya still hung up on his previous relationship with Mami, how long can this difficult client and reluctant rental girlfriend keep up their act? [Written by MAL Rewrite]

After years of animosity, the leaders of Osaka's Somei and Tokyo's Miyama yakuza groups have called a truce—by arranging an engagement between their respective grandchildren, Yoshino Somei and Kirishima Miyama. To this end, 17-year-old Yoshino moves to Tokyo to live with the Miyama family and attend school with her new fiancé. Although Kirishima is all smiles and perfectly polite, there is something unsettling about his demeanor that Yoshino cannot put her finger on. Yoshino's suspicions are soon confirmed: despite his manners, Kirishima is a masochistic maniac. He hurts people without batting an eye and also revels in being punished verbally and physically himself. What he wants most is a spoiled and arrogant fiancée who will ruin his life. When Yoshino does not quite meet his expectations, he reveals his true colors and openly insults her. However, instead of running away in fear, Yoshino decides to take revenge by making Kirishima fall in love with her and then ruthlessly breaking his heart.

Takashi Toono was unsure what to expect when he transferred to Morimori Academy, a private all-boys boarding school located deep in the mountains. However, it's no different from any other boys' school, and since he entered halfway through the year, he feels like an outcast—until the bright and friendly Kyousuke Yaguchi introduces himself. Due to the school's compulsory club policy, Toono chooses to join the low-effort "Photography Club," but the club is not what it seems. Nicknamed the "Yarichin Bitch Club," its members offer sexual services to pent-up boys at the academy—for no reason other than a love of sex. What's worse is his monthly sex quota—and the punishment for failure is severe: the club will forcefully take his innocence. However, as time runs out, Toono is left mortified and out of options. At Toono's side throughout his ordeal is Yaguchi, as well as Yuu Kashima—a fellow transfer student and club member who shares Toono's predicament. While the first years in the club struggle with their sticky dilemma, the club collectively has to deal with sex, secrets, and even stalkers! [Written by MAL Rewrite]

On Christmas Eve, four-year-old Miri Unasaka arrives in Tokyo completely alone, in search of her father. The bright lights and merry atmosphere guide Miri to a big hotel and a man with a delicious-looking cake. However, the child has just unknowingly walked into the center of an elaborate, foolproof plan for assassinating a dangerous mafia boss. Professional assassins Kazuki Kurusu and Rei Suwa live together, fleeing memories of their grim childhoods and avoiding emotional connections. When their mission goes awry and they end up bringing Miri home, there is only one reasonable thing to do: return Miri to her mother. But the girl's innocent laugh and pure worldview quickly enamor her to Kazuki, who secretly enjoys playing a parent, and it is not long before Rei's impenetrable heart makes room for Miri. Miri's every move is unpredictable, and Kazuki and Rei find raising an energetic child harder than any of their missions. Although it presents a great risk to their careers, Kazuki and Rei—both assuming the affectionate nickname "papa"—decide to provide Miri with a normal childhood despite all the odds stacked against them.