@jcwolf03 the thing is there are so many to pick from it would be really hard to definitively give you an answer. Hundreds if not thousands of cults have sprang up in the wake of ww2 to fill the spiritual vacuum that was created when the emperor was forced to publicly admit he wasn't an actual living god.
Probably the most notoriously of these cults culturally ( and so its a safe bet had some influence on the author) was probably Aum Shinrikyo, a death cult that ended up committing a coordinated sarin gas attack in the Tokyo's subways in the 90s that could have killed thousands of people if they hadn't thankfully bungled it. As it was a dozen people died and thousands of others got sick to varying degrees. At the height of their power Aum Shinrikyo made millions of dollars manufacturing drugs and guns for yakuza groups. ironically the police wrote them off as harmless prior to the gas attacks specifically because they had been doing business with the yakuza. The thinking at the time was basically that the yakuza would have already taken care of the cult themselves if it was an actual threat instead of doing business with them.
Not really sure if that answers your question or not, but I'm not deleting all that now.