Set in a futuristic world, there exist "Toys" which grant people superhuman abilities. This is responsible for a wave of crimes and necessitates employing Toy-using detectives to help solve them. Opera Kobayashi runs a detective agency, Milky Holmes, staffed by four aspiring young girl detectives who attend the Holmes Detective Academy, and each girl possesses their own unique Toy.

• Suzuko Mimori
• Mikoi Sasaki
• Izumi Kitta
• Satomi Akesaka
• Sora Tokui