Detective Opera Milky Holmes

During an encounter with a group of Gentlemen Thieves, the ace detective group Milky Holmes suddenly lose their Toys, which give them special abilities. A month later, they have since descended to being the worst student at Sherlock Holmes' Detective Academy. The Gentlemen Thief leader, Arsene, masquerading as the Student Council President, moves Milky Holmes into a less luxurious lifestyle inside an attic and gives them three months to recover their toys before they are expelled.

Milky Holmes have been neglecting their roles as detectives to tend to a vegetable farm they have been working on, which irritates Henriette who wants them to work on regaining their Toys. Noticing Henriette's depression, the Gentlemen Thieves take it upon themselves to get revenge on Milky Holmes by wrecking their vegetable farm, though this ends up evoking a murderous rage within them. After Milky Holmes are reminded about their roles as detectives, the matter is settled following a few explosions and Henriette's order to destroy the farm.

Alice and Kazumi are two friends who aspire to become great detectives like Milky Holmes. Whilst on a day out, they spot a thief and decide to pursue him. Although his escape is thwarted by the arrival of Milky Holmes, he is retrieved by other members of a group of thieves calling themselves Colors Phantom.