His nick is Jacky.
As for going with guys all I know is what spoon said above - girls only but I'd advice to buy him a drink and ask him or at least two different mamasans on two different visits.
Why ? Last year I was informed by mamasan guy I'm eyeing is girls only. Yet on next visit another mamasan was trying me to off the same guy. Did not materialize but occasionally mamasans have their own agendas so always talk to the source i.e. guy.
As for Jacky above I can add , girls only or not , on my two last visits in bar there was no visible girls presence in the audience and still he was all smiles and seemed to pay attention to guys seating. Certainly he will be happy to use a drink or two