In 1972, the Apollo 17 mission discovered a hypergate to Mars on the surface of the moon. Soon a war breaks out between Earth and Mars, and Martian soldiers begin to descend from the sky, riding steel giants, intent on exterminating humanity.
Naota is a normal Japanese 6th grade boy (although a little cynical), but when his older brother leaves for America to play baseball, his brother leaves his 17 year old girlfriend Mamimi behind. Mamimi is sending mixed signals and advances to Naota, and he doesn't know what to do about her. But to make matters worse, Naota's world is totally turned upside down when he is run over by a woman on a Vespa. During their first encounter, she hits him over the head with her guitar, which then causes a horn to grow out of his forehead. She calls herself "Haruko" and her presence changes Naota's life to even further insanity.
In the future Japan has become a fractured country, and small towns now exist. The rulers of this world have the cursed power of Telekinesis. When an incident occurs, 5 children come to realize the world is not as it seems, and learn the bloody history behind this world. These 5 children unite and help the world as it falls into a downward spiral of chaos.
Himari Takakura passes away after going out on a trip with her brothers, twins Kanba and Shōma. She was, however, miraculously saved by a spirit in a penguin-shaped hat. In return for her extended life, the twins must search for an item known as the Penguin Drum with the aid of three penguins, which are visible only to the siblings.
After experiencing a bizarre dream, Madoka Kaname, a kind 14-year-old girl, encounters a magical creature named Kyube. Madoka and her friend Sayaka Miki are offered the opportunity of gaining magical powers if they agree to make a contract with the strange little being. He will also grant them one wish, but in exchange they shall risk their lives by accepting the responsibility of fighting witches. Invisible to human eyes, witches are catalysts of despair in the areas they inhabit. An ally of Kyube, a magical girl named Mami Tomoe, befriends and encourages the two girls to accept the contract. For an unknown reason, another magical girl named Homura Akemi is determined to prevent Madoka from accepting the deal.
Lain Iwakura appears to be an ordinary girl, with almost no experience with computers. Yet the sudden suicide of a schoolmate, and a number of strange occurrences, conspire to pull Lain into the world of the Wired, where she gradually learns that nothing is what it seems to be... not even Lain herself.
Steins;Gate is set in the summer of 2010, approximately one year after the events that took place in Chaos;Head, in Akihabara. Physical locales of Akihabara like the Radio Kaikan building can be spotted in the game. According to Chiyomaru Shikura, who headed the planning of Steins;Gate, Akihabara was chosen because it is an easy place for acquiring hardware parts, which makes it the ideal place for people interested in inventing and tinkering with things. The notion of time and time traveling are the main themes of the game. The concept of cause and effect is featured prominently in the game as the protagonist travels back in time numerous times to perform different actions in an attempt to alter what has happened in the future.
After moving into the quiet town of Hinamizawa, Maebara Keiichi spends his days blissfully in school often playing games with his local friends. However, appearances can be deceiving. One fateful day, Keiichi stumbles upon news of a murder that had occurred in Hinamizawa. From this point on, horrific events unfold in front of Keiichi, as he soon learns his close friends may not be all that they seem. Based on the amateur mystery game by 07th Expansion, the story is told in a series of different scenarios.