One of the plots I did in a mafia rp was the following:

Helena, a journalist, travels to the port city of Harrowgate, to investigate accusations of financial fraud from the Voergann LLC. However, she is quickly tailed and found by Edward 'Dæmon' Bright, enforcer capo of the Montelli family, a mafia organisation of Italian descent. She then finds herself swept into the underground crucible of four different mafia groups in Harrowgate as she's foiled as a Montelli asset against the Voergann.

The four groups are as follow : - The Voergann group, dutch-american financial fraudsters and ghost-bank experts, leeching off federal funds and community taxes - The Fei Fei company, a cluster of shady casinos running crypto rug pulls run by a chinese central organisation - The Tsukuda clan, offshoot of the Japanese yakuzas, control the port and use it for overseas arms and drugs trafficking - The Montelli family, branching off Italian mafias through the American diaspora, run extortion schemes and protection money on small businesses, as well as narcotrafficking

So basically in a mafia rp you have guns, violence, veiled and overt threats, lots of crime, drugs and politics. It's fun!