"... but what happened to her? This is weird and it's giving me a bad feeling."
"'What happened to her?' You should listen to yourself. What do you think happened to her? What happens to anyone?"
" I mean, if it was one of the other cartels she wouldn't just vanish like this."
"So now you're some big expert on the cartels? Please enlighten me, aniki."
"Shut up. You know what I mean. They would have moved in on the lab or something. They wouldn't just leave it. And the Firemen would have taken credit. No way would they pull off something this big and not want to be known for it."
"... which means I'm right."
"It doesn't prove anything. That's a myth."
"It totally isn't! You screw up and the Mountain gets you. Everybody knows that! It just shows how powerful he is that he didn't even care about upsetting Soshi-oyabun. For all we know he might be an actual oni!"
"There isn't some oni going around killing people! This is just like when you were claiming that there was a big war brewing between rival ninja clans. Besides, you said that Yuuki knew a guy who claims he was beat up by the Mountain. No oni would just beat a guy. Even if he exists — which he totally doesn't — he's probably only some big, tough guy. People just don't want to admit they got their asses kicked."
"Either way. What really matters is that Watchful isn't coming back. Whoever did it might come for us next. Or even worse, Soshi-oyabun will take it out on us anyway. I say we get the fuck out of town as soon as possible. Money's no good if you're not alive to spend it.
And oni are totally real! Why, a friend of mine was out in the fields outside of town a few weeks ago and he *swears* that he saw..."
Ichiro Taiki referred to himself as "The Mountain" when being goaded by Mirumoto. Presumably he forgot who he was speaking to in the heat of the moment and attempted to rely on the fearsome reputation he has acquired as a bogeyman of the underworld.