This is one part of Japanese society I know very little about. My wife always talks about yakuza being bad but can’t provide an details other than “they are bad.”
She hates going to Kabukicho but it never feels particularly unsafe to me where as in the US there’s definitely places I would avoid at all cost.
I don't know much about gangster's in Japan, but I'd say from my limited experience that they manage basically gray-market and black-market businesses. E.g. hostess clubs and adult entertainment, some of the general entertainment industry, maybe drugs to a small extent, loan sharking, gambling and other related things.
I would say that the violence typically doesn't bleed out to the general population unless you get invovled in some way, but you will get ripped off if you do business with them (again, I have very limited experience with this).
As a low-level gangster, he probably was trying to get people on the street to attend an adult entertainment location (or scouting new actresses) and do general gopher jobs for higher-ups.
Edit: Yeah, Kabuki-cho isn't that bad to be honest. To see the real dangerous Yakuza part of town, you have to go to Yoshiwara. I went there with a local and there was a dude walking around with no shirt and carrying a sword over his shoulder. He told me to not look anyone in the eye. There were police on each side of the street.
- A delinquent student I had who dropped out in junior high caught up with me and told me how he went to jail and was a low level gangster.
- I also knew an Australian older guy who got jumped by some teenagers when he was drunk.
- Also a drunk guy tried to hit on a girl I knew while we were walking to the train station and literally tried to physically drag her somewhere and hit my other friend who wanted to talk to him peacefully.
- A creepy old guy showed two junior high girls a binder full of pictures of underage girls in a supermarket food court and was trying to proposition them or something. My friend used to be their English teacher and confronted him in Japanese. When I turned to look at the supermarket, everyone was dead silent mouth agape. The old security guard lady who worked there was crying.
- I believe I also spoke to a cop or an older person who said during the earthquake their was concern of people stealing or commiting crimes and they'd do it quietly.
- There's also the women's only train in place because of chikan or train perverts who try to grope women during rush hour. I don't know of many other countries that have it.
I definitely think Japan is one of the safest countries in the world. I left my phone on a bike and found it still there hours later, but there's definitely crime. I also don't know if it's great to conflate yelling, littering, etc. with crime, but there's definitely a correlation.