Daisuke Todoroki is a character from the Persona 2 duology.
Persona 2: Innocent Sin
Ten years before the events of the game, he was hired by Junko Kashihara to investigate her husband Akinari, as she suspected the latter was cheating on her with Maya Okamura. Todoroki ultimately concluded that the two were not having an affair, but became suspicious of them due to the way the two and Tatsuya Sudou were investigating landmarks around the city. He followed the three as they investigated Mt. Katatsumuri and became convinced that they were looking for hidden treasure.
The following day, he followed them to Seven Sisters High School, but Akinari noticed him following him, and, convinced that Todoroki was a member of the Last Battalion, refused to leave the house afterwards. Akinari eventually left the house with his son prompting Todoroki to follow them. When Todoroki followed him to the school, Akinari noticed him and fled into the school. Todoroki would later learn that Akinari died by falling into the gears of the clock tower shortly after.
By the time of Innocent Sin, Todoroki had gained a sudden surge of competence (implied to be due to him being possessed by Kyouji Kuzunoha) and has hired Tamaki Uchida and Tadashi Satomi as his assistants. He will spread rumors for Tatsuya Suou for a fee.
Persona 2: Eternal Punishment
"He used to be a flunky, but he all of a sudden got smart. Now he works as a Devil Summoner."
- Close examination of Todoroki's brooch reveals it bears the symbol of the Kuzunoha Clan, furthering the evidence that Todoroki isn't exactly himself at the moment.