Hatsuki is a highschool student living with her sister, Hatsumi, who she has a huge crush on. On Hatsumi's 16th birthday, she is suddenly surrounded by a green light and disappears in front of Hatsuki. She manages to follow Hatsumi with the help of a being resembling a fat baby chick (literally), ending up in a place called "The Great Library", which is full of different worlds stored in books. Hatsumi wasn't there, though, so the search for Hatsuki's great love begins and involves traveling from book to book. (Source: AniDB)

Kei Kunieda is a newscaster who strictly maintains an amiable and kind persona while at work. Although he smiles on the outside, he covertly curses at others to his heart's content. His everyday life is smooth, even if he keeps half of himself hidden at all times, but that changes when he meets Ushio Tsuzuki, an independent stop-motion animator. Soon, Kei finds himself caught in a lie borne from his two personas meeting Ushio under different conditions, with the other man unaware they are the very same person. As feelings begin to blossom between them, Kei cannot be sure if Ushio will love both sides of him—or only just half. [Written by MAL Rewrite]

Hiiragi Kyouichirou is a boy who travels from his provincial town to Tokyo to attend university. He carries with him his family's sword to protect himself. When he arrives in Tokyo, he becomes swept up in a plot by the Imperial army. (Source: ANN)

Upon hearing news that his mother was on verge of death, Haru Kaidou—the eldest son of the family—flies all the way to Canada. The moment he arrives, he learns that not only did his mother fool him, but he is also supposed to take care of his adoptive brother, Ren Kaidou, an antisocial kid who feels more comfortable around dogs than people. Due to his new brother's distrustful nature, Haru initially has a hard time reaching out to Ren but their relationship eventually grows. He makes a promise to Ren: they will live together in Japan after Haru graduates from high school. However, due to an unfortunate accident, Haru loses all memories of the summer they spent together, including the promise he made. Five years later, expecting Haru to keep his promise, Ren arrives in Tokyo; but to Haru, Ren is just a random boy claiming to be his brother. [Written by MAL Rewrite]