@exocel Is it about about chapter 396? It's the good old "it's me" scam, they pretend to be your kid/grandkid on the phone in order to scam lonely people who haven't seen their kid/grandkid in a long time. But they never actually give their name.
Something along the line of:
S-"Hey mom it's me"
M-"Maruyama? why are you calling me after all this time? and why does your voice sound different?"
S-"Yes mom, it's me, Maruyama don't tell me you forgot about me? As for my voice, I caught a cold mom, nothing bad. But listen, I ran into a bit of trouble so could you wire me some cash please?"
and so on and so forth. They basically use the same tricks a fortune telling would use, to trick their target into giving them all the information they need to scam you. (For example, above, the mother gave the name and that it had been a while since they talked, like a dumbass)