Naoya Mukai is having the time of his life after his childhood friend Saki Saki finally accepts one of his countless confessions. Ensuring that their relationship will stay strong, he spares no effort in showering affection to his now beloved girlfriend. However, one afternoon, another girl named Nagisa Minase suddenly confesses to Naoya following months of preparation. Even though he politely rejects her, Nagisa's irresistible charm and determination continue to attract Naoya. Wanting to fulfill both Saki and Nagisa's desires, Naoya ends up proposing a crazy idea—to date the two of them simultaneously, with both girls fully aware. This unprecedented state of affairs ultimately causes wacky and hilarious situations in whatever they do to keep their unusual relationship going.

A series of eerily similar suicides occupy newspaper headlines in late '90s Japan. Amidst all the bizarre resemblances, there is one detail that stands out above the rest: the victims have all taken their lives by leaping from the Fujou building, a run-down abandoned structure rising high above the city. Shiki Ryougi, a cold-hearted girl living in an empty apartment, suspects that these sinister events have a supernatural cause. Possessing a mystical power herself, Shiki works to investigate the incidents alongside Touko Aozaki, a doll-making detective specializing in magic, and her friend Mikiya Kokotou who works as Touko's assistant. Shiki unravels the mystery as she ventures through an enigmatic world to uncover the dark secrets surrounding the strange phenomenon.

In August of 1995, Mikiya Kokutou meets a young kimono-clad woman named Shiki Ryougi. When he finds out that they go to the same school, he attempts to befriend her. Though her upbringing is unconventional and she herself is strange, Mikiya is not deterred, and Shiki gradually opens up to him. But Mikiya's life will be changed forever by this simple meeting, and in ways that he never imagined, as he begins to see a deadly side to his new friend...

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?