Through their tutor Fuutarou Uesugi's diligent guidance, the Nakano quintuplets' academic performance shows signs of improvement, even if their path to graduation is still rocky. However, as they continue to cause various situations that delay any actual tutoring, Fuutarou becomes increasingly involved with their personal lives, further complicating their relationship with each other. On another note, Fuutarou slowly begins to realize the existence of a possible connection between him and the past he believes to have shared with one of the five girls. With everyone's feelings beginning to develop and overlap, will they be able to keep their bond strictly to that of a teacher and his students—or will it mature into something else entirely?

Hitohito Tadano is an ordinary boy who heads into his first day of high school with a clear plan: to avoid trouble and do his best to blend in with others. Unfortunately, he fails right away when he takes the seat beside the school's madonna—Shouko Komi. His peers now recognize him as someone to eliminate for a chance to sit next to the most beautiful girl in class. Gorgeous and graceful with long, dark hair, Komi is universally adored and immensely popular despite her mysterious persona. However, unbeknownst to everyone, she has crippling anxiety and a communication disorder which prevents her from wholeheartedly socializing with her classmates. When left alone in the classroom, a chain of events forces Komi to interact with Tadano through writing on the blackboard, as if in a one-way conversation. Being the first person to realize she cannot communicate properly, Tadano picks up the chalk and begins to write as well. He eventually discovers that Komi's goal is to make one hundred friends during her time in high school. To this end, he decides to lend her a helping hand, thus also becoming her first-ever friend.

If a survey were conducted to see if people believed in aliens, time travelers, or maybe espers, most would say they do not; average high school student Kyon considers himself among the non-believers. However, on his first day of school, he meets a girl who soon turns his world upside down. During class introductions, the beautiful Haruhi Suzumiya boldly announces her boredom with normal people and her intention of meeting supernatural beings. Dumbfounded, Kyon learns of her frustration with the lack of paranormal-focused clubs at their school and unwittingly inspires her to start her own club. She creates the Spreading Fun all Over the World with Haruhi Suzumiya Brigade, otherwise known as the SOS Brigade. Following the SOS Brigade's founding, Haruhi manages to recruit Kyon and three other members: quiet bookworm Yuki Nagato, shy upperclassman Mikuru Asahina, and perpetually positive Itsuki Koizumi. Despite their normal appearance, the new members of the SOS Brigade each carry their own secrets related to Haruhi. Caught up in the mystery surrounding the eccentric club leader, Kyon is whisked away on a series of misadventures by Haruhi and the SOS Brigade, each one bringing him closer to the truth about who and what she is.

Eighteen-year-old Tsukasa Mizugaki has failed his college entrance exams, but after pulling some strings, he manages to land a job at the Sion Artificial Intelligence Corporation. SAI Corp is responsible for the creation of Giftias—highly advanced androids which are almost indiscernible from normal humans. However, unlike humans, Giftias have a maximum lifespan of 81,920 hours, or around nine years and four months. Terminal Service One, the station Tsukasa was assigned to, is responsible for collecting Giftias that have met their expiration date, before they lose their memories and become hostile. Promptly after joining Terminal Service One, Tsukasa is partnered with a beautiful Giftia named Isla. She is a Terminal Service veteran and considered the best in Giftia retrievals, contrary to her petite figure and placid nature. Time is fleeting though, and Tsukasa must come to terms with his feelings for Isla before her time is up. No matter how much someone desires it, nothing lasts forever.