As introverted colleagues at a travel agency in Tokyo, Takuya Oohara and Rika Honjouji both cherish their happily single lives. After work, home is where they feel most at ease: Takuya unwinds with his cat, while Rika studies various maps. However, an uncertain future looms over their treasured tranquility when their company plans to open a branch office in Alaska within one year and transfer an unmarried employee there. During a day off, Takuya and Rika accidentally meet and, despite never having spoken before, open up to each other about their relocation fears. Feeling encouraged by Takuya facing the same predicament, Rika suddenly proposes a daring solution—to pretend to be engaged for 365 days. Takuya accepts, but little do the two know that the path to marriage may, in many ways, change forever the very lifestyles they struggle to preserve.

After a year in America, Kurisu Makise returns to Akihabara and reunites with Rintarou Okabe. However, their reunion is cut short when Okabe begins to experience recurring flashes of other timelines as the consequences of his time traveling start to manifest. These side effects eventually culminate in Okabe suddenly vanishing from the world, and only the startled Kurisu has any memory of his existence. In the midst of despair, Kurisu is faced with a truly arduous choice that will test both her duty as a scientist and her loyalty as a friend: follow Okabe's advice and stay away from traveling through time to avoid the potential consequences it may have on the world lines, or ignore it to rescue the person that she cherishes most. Regardless of her decision, the path she chooses is one that will affect the past, the present, and the future. [Written by MAL Rewrite]

Yuuta Hibiki wakes up in the room of Rikka Takarada and notices two things: he has no memories, and he can hear a mysterious voice calling his name from a nearby room. On further inspection, he finds a robot—which introduces itself as Hyper Agent Gridman—behind the screen of an old computer. Much to Yuuta's surprise, Rikka cannot hear Gridman, nor can she see the ominous monsters looming over a thick fog as it envelopes the town outside. Another giant monster materializes in the city and proceeds to wreak havoc. Amidst the confusion, Yuuta is once again drawn to the old computer and merges with Gridman. Suddenly, he appears in the middle of the battle and is forced to fight the monster. Together with Rikka and fellow classmate Shou Utsumi, Yuuta forms the "Gridman Alliance" to defeat the monsters plaguing the city and find whoever is responsible for their emergence. [Written by MAL Rewrite]

When mundane office worker Kiyoshi Adachi turns 30 years old, he discovers that he has gained the ability to read minds due simply to remaining a virgin for his entire life. The caveat, however, is that he must make physical contact with a person to know what they are thinking about. Adachi believes there is no real use for this power until he accidentally hears the thoughts of his coworker, Yuuichi Kurosawa. Charismatic and dependable, Kurosawa is the star of Adachi's team at work, earning praise and admiration from everyone at the office. But deep within, Kurosawa harbors an intense one-sided crush for the gloomy Adachi—a fact that Adachi only learns because of his ability, and knowledge he tries to respectfully disregard. As Kurosawa treats Adachi with kindness and affection he has never experienced before, Adachi finds it increasingly difficult to ignore his coworker's genuine advances.