Koto unknowingly seals away the Sun Goddess Amaterasu, and now she is in a different world and can't return. Meeting priestesses who combat the evil in this strange place she learns that Black Towers throughout the land keep Amaterasu sealed away and are guarded by evil monsters. Koto must now find a way to help defeat these monsters and return the world to the way it was. (Source: ANN)

Set in the near future in the Great Era of Detectives, chosen people are born with supernatural abilities known as Toys (トイズ, Toizu). Those who use these Toys for evil are responsible for a wave of crimes and necessitate employing Toy-using detectives to help solve them. In the Yokohama District, Opera Kobayashi runs a detective agency named Milky Holmes, made up of four budding young detectives, Sherlock Shellingford, Nero Yuzurizaki, Hercule Barton and Cordelia Glauca, who each wield their own unique toys and train to become detectives at Holmes Detective Academy. The video game casts players in the role of Kobayashi, who must utilise Milky Holmes' unique abilities to stop the Thieves' Empire, a band of thieves led by the mysterious Arséne. The second puts players in the role of another detective, Ellery Himeyuri. The Alternative TV specials also take place in this universe, in which Kobayashi and Milky Holmes are assisted by another Toy user, Lily Adler, in fighting against the Thieves' Empire whilst visiting London. In the first two anime television series, the four girls of Milky Holmes, Sherlock, Nero, Hercule and Cordelia, end up losing their Toys during an encounter with the Thieves' Empire. Taken away from their rich lifestyle and thrown into an attic, the girls must try and regain use of their Toys or else face expulsion from Holmes Detective Academy. Futari wa Milky Holmes, which takes place two years after the other series, follows two young girls, Alice and Kazumi, who, inspired by Milky Holmes, form their own detective unit, Feathers, and fight against a group of thieves known as the Color the Phantom. Tantei Kageki Milky Holmes TD sees Milky Holmes help an idol named Marine Amagi recover her Toys, the seven Elements, which have been stolen from her.

Masane Amaha and her daughter Rihoko are on the run from a government child welfare agency that wants to take Rihoko away from her mother. They are caught and Rihoko is taken away. Meanwhile, Masane is attacked by an advanced weapon that can disguise itself as a human being. When faced with the danger, a strange light emits from her wrist and she transforms into a powerful being. She destroys the weapon and consequently becomes involved in a power struggle between powerful organizations, with her at the center of their attention. Because she holds the greatest power of them all, the legendary Witchblade. (Source: AniDB)

Hundreds of years ago, the borders between the worlds of humans and youkai temporarily overlapped, resulting in many residents of both crossing over to the other side. In the years since this event, the city of Sakurashin has become a central hub for all inter-dimensional affairs—a result of both the sacred Seven Pillars around the city serving as a beacon for the youkai, and the efforts of the Hiizumi Life Counseling Office in keeping the townsfolk happy. This office is composed of Hime Yarizakura, the young mayor of the city; satori Ao Nanami, who can read people's minds; half-youkai Kotoha Isone, who can summon anything by speaking a word; oni siblings, Kyousuke and Touka Kishi; and the office director Akina Hiizumi, who inherited his family's ability to force youkai back to their world. Besides volunteer and arbitration work, the Life Counseling Office also suppresses any Strikes: rare occurrences where humans are suddenly infused with youkai powers and go on a rampage. But the appearance of a sinister man signals trouble as Strikes become increasingly common, political rivals make their moves, and malicious individuals descend upon the city. As the self-appointed defenders of Sakurashin, it's up to the Life Counseling Office to protect the idyllic city they call home! [Written by MAL Rewrite]