On her first day of junior high school, Mato Kuroi meets Yomi Takanashi. Though Yomi is initially taken aback by Mako's straightforward personality, the pair quickly becomes friends and begin to spend time together daily. As a sign of their friendship, Mato gives Yomi a cell phone charm—a blue star, identical to her own. However, when the two enter their second year, their relationship starts to change. Placed in a different class, Mato begins to spend more time with Yuu Koutari instead, a girl she met through the basketball team. In fact, the former best friends drift apart so much so that Mato cannot find Yomi anywhere, as if she had disappeared entirely. Elsewhere, Black★Rock Shooter is on a quest to vanquish the Dead Master. These two, while opposed, bear a connection not unlike Mato and Yomi. As their stories begin to cross, it seems Yomi's disappearance may have to do with the blue star-shaped charm and the legendary gunslinger herself.

In the final years of the Bakumatsu, wandering mercenary Yojiro Akizuki travels the length and breadth of Japan. And while he employs his sword in the usual fashion, he also uses it to help him locate supernatural items which he pursues with single-minded determination, often with bloody results. In the course of his quest, he crosses paths with a traveling theater group whose members have their own dark agenda. Is it a chance meeting or the result of some, as yet, undiscovered conspiracy?

Sana is not an ordinary little girl; she possesses a special ability known as "Alice's Dream." Due to her power, which allows her to create anything from her imagination, all that she knows is the laboratory where she is a test subject. Wishing to experience the outside world, she escapes and meets a stubborn old florist named Zouroku Kashimura in a convenience store. All too soon, her pursuers catch up and Zouroku is roped into Sana's troubles. However, far from trying to distance himself, Zouroku extends a hand to help Sana. Following his values and sense of justice, he even gives the pursuers a piece of his mind! Zouroku then offers Sana a place to stay, beginning the daily life and struggles of the unlikely duo. [Written by MAL Rewrite]

Aine Yuuki, who is a regular student at Star Harmony Academy's normal division, meets Mio Minato from the idol division, who invites her to join Aikatsu to fulfill Aine's goal to make friends. She also befriends Maika Chōno and Ema Hinata who are also idols. Aine and Mio form a pair to become best friends to become the bright "Diamond Friends". Karen Kamishiro and Mirai Asuku are categorized as "Diamond Friends" and are in the Diamond Class! (Source: Wikipedia)