Addressing other members of the same great family when everyone shares the same surname


Hypothetical situation, let's say we have a great familly meeting, where
everyone have the same surname but some members of the familly see each other
for the first time. Of course, introductions are made, so everyone knows each
other names. Here goes my question: How would one person address the other
when they barely know each other? I mean, they can use the surname, but that
would be confusing, since everyone has the same. Will they make an exception
and use their names instead, even though they see other members of the familly
for the first time?




Of course they use their individual names (+ san).

