When Marge is out for a crazy bowling night with the girls, she discovers all the men of Springfield are gone... at a MMA event.  When she sees Bart fighting at school and Homer encouraging it, she decides to protest the sport.  She grabs a microphone at one of the events during a protest, and the creator agrees to cancel the show if she can defeat him in a fight.  She begins training with multiple trainers around Springfield and eventually goes through with the fight.  She's initially losing and Bart steps in to defend her.  When the promoter begins to beat up Bart, Marge's mother instincts take over and she whoops the crap out of the guy.