Is there a way of finding Mira without having to have Sammy prostitute herself?
I played the game quite a lot and didn't find another way. But then again, this game has a lot of quasi-hidden content so who knows?
Otherwise, try asking on discord.
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I think theoretically you could gather the necessary information without doing real street work. You will still have to become a prostitute but you won't have to put out for real. Just standing around so to speak and talking to the other girls for example. But I never tried it since this is much, much slower and I'm always scared that Mira might die in the meantime. But if you want to abuse the save function, this should be possible.