"Sheryl, Nero, Elly, and Cordelia are the most popular students at Holmes Detective Academy, because of the many cases they've solved with their Toys and teamwork. The students and the people of the Detective City Yokohama all look up to the members of "Milky Holmes", as they're called. But on a dark and stormy night, during a battle with their rivals "The Gentlemen Thief Empire", they lose their toys, and their fate undergoes a dramatic change..."

[Source: Crunchyroll]

A special program of Tantei Opera Milky Holmes produced by the staff of the TV series.

After some pushing by Irene and her father and a lack of support otherwise, Kokoro stubbornly quits her job as a police detective to become an idol. She soon finds the idol life draining and starts to miss her old detective life. When Henriette notices Sherlock's loneliness without her, she stages a statue theft in order to convince Kokoro to return to the force.

[Source: AniDB]

Milky Holmes is a detective team composed of four girls who descended from famous detectives and possess supernatural powers known as "Toys". In this alternative world, instead of losing their Toys and becoming worthless students, they are on the path to becoming successful detectives. Under the guidance of Kobayashi Opera, they work to solve mysteries.

[Source: AniDB]

Third season of Tantei Opera Milky Holmes.

In the story, the Great Era of Detectives — when detectives and thieves with a power known as "Toys" compete — has given way to the Great Era of Idols. However, someone starts stealing the idols' songs in Yokohama. When super idol Marine Amagi's hit song "Kiseki no Uta" (Miracle's Song) is stolen, she enlists the detectives of Milky Holmes.

[Source: Anime News Network]

The film will feature a three-way battle between The Gentlemen Thief Empire, the Genius 4, and the Milky Holmes groups. Just as the Milky Holmes group is settling down to relax at a hot spring after their study tour, an alarm goes off, because The Gentlemen Thief Empire intend to steal a treasure. The two groups start to battle for who gets to use the "Toys," when suddenly the Genius 4 rush to the scene.

[Source: Anime News Network]

Milky Holmes are doing well and solves cases one by one. Student council suddenly thought they should get graduated from the academy, and gave them a graduation test. The content of the graduation case she chose is... Aichi Sendou's Card stolen case!

[Source: MyAnimeList]