When Yumi Fukuzawa entered the Lillian Girls' Academy, a prestigious all-girls Catholic school in Tokyo, she never imagined she would catch the eye of beautiful and demure Sachiko Ogasawara, one of the school's most popular students. Now Sachiko has offered to be Yumi's soeur, her sister and guide for all her years at the academy. The whole idea has Yumi completely flustered—after all, they hardly know each other! The entire campus is abuzz with rumors about the two of them, but Yumi is conflicted over accepting Sachiko's offer. While she admires Sachiko, being her soeur would also mean constantly being at the center of the entire school's attention! (Source: RightStuf)

Two years after meeting Aoi, Kaoru and gang are still up to their normal habits. Kaoru now in grad school and the tenants being as rowdy as ever what will become of Aoi and Kaoru's love. Two years has passed since Aoi and Kaoru were freed from the bonds of their families. They continue to live their normal lives with their usual friends in their house.

On Christmas Eve, Hiro Hirono runs into Miyako Miyamura, a frivolous girl who borrows his bicycle in order to chase down a purse thief. After Hiro finds his bicycle wrecked and Miyako unconscious, the two unexpectedly spend their Christmas Eve together, and when they discover they go to the same high school, their accidental relationship develops even further. This sparks the jealousy of Hiro's childhood friend Kei Shindou, whose pure approach to life catches the eye of Kyosuke Tsutsumi, a womanizing photographer searching for the perfect shot. Elsewhere, Renji Asou, a boy who dreams of being a girl's knight in shining armor, has a chance encounter with Kei's twin sister—the overly shy Chihiro Shindou, who spends her time reading alone—at an abandoned train station. The two quickly become friends and eventually decide to write a novel together. However, when Renji discovers Chihiro's secret, his childish ideals are put to the test. Guided by two mysterious adults, these youths' relationships intertwine in a heart-rending tale of love, rejection, acceptance, and memories.

Within the domed city of Romdo lies one of the last human civilizations on Earth. Thousands of years ago, a global ecological catastrophe doomed the planet; now, life outside these domes is virtually impossible. To expedite mankind's recovery, AutoReivs, humanoid-like robots, have been created to assist people in their day-to-day lives. However, AutoReivs have begun contracting an enigmatic disease called the Cogito Virus, which grants them self-awareness. Re-l Mayer, the granddaughter of Romdo's ruler, is assigned to investigate this phenomenon alongside her AutoReiv partner, Iggy. But what begins as a routine investigation quickly spirals into a conspiracy as Re-l is confronted by humanity's darkest sins. Elsewhere in Romdo, an AutoReiv specialist by the name of Vincent Law must also face his demons when surreal events begin occurring around him. Re-l, Iggy, Vincent, and the child AutoReiv named Pino will form an unlikely faction as they struggle to uncover Romdo's mysteries and discover the true purpose of the mythical beings called Proxies.