Delinquent Girl Detective

After being incarcerated in a youth corrections facility, Saki Asamiya is recruited by a detective named Jin which convinces her that the government could provide clemency for her mother on death row.
He trains her to be an undercover youth detective, infiltrating several high schools in Japan to investigate cases of crime, corruption and terrorism: it's the birth of a high school student legend.

Note: Volume count based on the bunkoban.