I feel like there's a chance Matt is at least acquainted with Ranmaru. He's younger than her, 32, so he'd still be a kid during her "gang days" but at the time his father was a cop and might have dealt with her case. Little Matt might have heard the story about the girl who beat up multiple people all at once for her friends and he'd think that was totally cool. Not sure they'd meet at that age but either way they could have met somewhere on the streets of the city at some point.