|First Appearance'||Tantei Opera Milky Holmes|
|Voice Actor||Shuta Morishima|
Opera Kobayashi is the main protagonist of the Tantei Opera Milky Holmes games. He trained the four Milky Holmes girls as detectives and the skills to use their Toys. He never truly makes an appearance in the TV series, except during the two-part special, Tantei Opera Milky Holmes Alternative.
In the PSP game, he is the main protagonist who is said to be the person who trained Milky Holmes. In the PSP game, he lost his Toy much the same as the Milky Holmes.
- While not a regular anime character; he makes the following appearances;