The most moe detective group that you'll ever see.
Milky Holmes is a group of detectives containing four girls. Sherlock Shellingford, Nero Yuzurizaki, Hercule Barton, Cordelia Glauca. These four aren't your 'typical' detectives, each of them has a special power (usually referred to as 'Toys') which they use to fight the Gentlemen Thieves.
The girl detective group served their academy for a long time, leading them to be well-known and respected. All of their achievements, however, proved that they can win to any obstacle standing on their way — friendship-wise and when it concerned their intelligence.
But when one day, all of them lose their precious Toys, they become the school's laughing stock; losing all their VIP privileges and even their beautiful suite, Milky Holmes has to face a huge challenge. Losing Toys might be easy, but how about re-gaining them?
Worth noting is that in the anime, Opera Kobayashi, who guides Milky Holmes in the Visual Novel and is the main protagonist of it, is not a main character. He, however, is the one who runs the detective agency of Milky Holmes.
In Tantei Opera Milky Holmes 2 Visual Novel, a new female protagonist is introduced, her name being Ellery Himeyuri. She is put in charge of the detective agency after suddenly gaining Toys.