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)

The mysterious, yellow-masked Storyteller is a man whose true name and origin are both unknown. He appears at dusk where children gather and recites sinister tales based on Japanese urban legends, to which his young audience eerily intakes. However, the Storyteller is no ordinary teller of tales. He incorporates a kamishibai, a traditional paper-scrolling device, to add visuals to his already demented narration. A series of short horror stories, Yami Shibai begins with a bachelor who, after moving into a new apartment, immediately starts sensing a malevolent glare being pressed into him. A single talisman rests on his ceiling, but he has no way of knowing it is one of the few safeguards that separate him from a bottomless pit of suffering. Each story is more terrifying, more appalling, and more sickening than the last as the Storyteller's audience find themselves being sucked into the vicious world of his words. [Written by MAL Rewrite]

Alternative version of final four episodes of High School DxD BorN.