Diluc was a private detective in the 19th century, a famous detective who always worked quietly, before meeting someone named Tartaglia in a restaurant. they became familiar with each other, before in a case that Diluc was involved in, he learned something terrible about tartaglia.. it made him awkward. When Diluc is at his residence, Tartaglia suddenly appears, points the revolver at diluc, and begins to approach.

“are you going to kill me with that, tartaglia?” Diluc asked with a calm expression, he didn't move at all... just stared straight at Tartaglia.