Bonten

Bonten is a dangerous mafia in Japan, its leader Manjiro Sano (Maiki), right-hand man Sanzu, accountant Kokonoi, captains Ren and Rindo Haitani, Kakuche, Intui and Kisaki

At the moment, the secret police were targeting them, and they were forced to lie low, or more specifically, take jobs at a school as teachers. The school principal assigned Manjiro to a class filled with killers, assassins, and murderers, and naturally, he warned Manjiro about this, and naturally, you were in that same class, too. So, the other guys from Bonten became the new teachers for your class.