Mikami Inaba was fighting a person from another school on her school's rooftop. As they fought, her friend Haru appeared. Seeing Mikami distracted, the man charged at her, causing both of them to break the nearby rabbit cages & fall off the roof. As Mikami fell, she desperately grabbed the rabbit. Suddenly, a flash or pink light appeared. Mikami fused with the rabbit, and gained another personality, called Mimika. Now, Mikami only appears when various people threaten her and her friends. Otherwise, she takes on the form of Mimika. (Source: ANN)

Not much is notable about the lecherous Ataru Moroboshi, but his extraordinary bad luck sticks out like the horns in an alien's head. When Earth is threatened by a fleet of alien invaders known as the Oni, Ataru is selected to represent humanity in a duel against one of them. It is a stroke of rare luck for Ataru that the duel is in fact a game of tag, and that his opponent is Lum, daughter of the Oni's leader, who places her personal dignity above victory—as Ataru finds out by seizing Lum's bikini top and with it, victory. However, misfortune kicks in again when Lum mistakes Ataru's promise to marry his girlfriend, Shinobu Miyake, as the desire to wed Lum herself, and decides she rather likes the idea. Wielding her influence as an alien princess, she moves in with him. Forced to deal with the consequences of his womanizing ways, Ataru must balance his crumbling relationship with Shinobu while keeping Lum happy, all the while flirting with every woman he meets.

The anime centers on the members of the real-world four-member male vocal unit Urashimasakatasen. Uratanuki, Shima, Tonari no Sakata, and Senra appear in the shorts as high school students. (Source: ANN)

Kaori Sasaki—a member of Uchihama Academy's Astronomy Club—confesses to Sou Akiyama, but later that evening, she dies in a tragic road accident. Her friends and fellow club members mourn her death in a local hospital. Yet she shows up to school the following day, and no one senses anything amiss. The day finishes without any unusual incidents, and the group of friends plans for the upcoming cultural festival. Suddenly, the room is shaken by an unnatural earthquake. Everyone splits up to investigate—except for Nagisa Hanamiya, who stays behind. As everyone leaves, Nagisa notices that the odd relic-like cube that she was toying with starts emitting a strange blue light. Meanwhile, Sou stumbles upon an unconscious, naked girl lying in a pool of water. Ushinawareta Mirai wo Motomete follows the Astronomy Club's increasingly bizarre adventures—from dealing with ghosts to quelling unrests between student clubs. All the while, they unravel the circumstances behind the sudden appearance of a new transfer student.