My takeaway of the cool dynamic at work here is that universally (but particularly in Japan) no one wants to be seen promoting themselves. Especially for older people they've done so many cool things, and are currently doing cool things now that they're retired and have free time, but socially it's a bit awkward to just ask, what cool and interesting stuff can you tell me about.

And the physical / game medium helps connect intergenerationally as well. But actually I could see this kind of trading card dynamic working in other situations like business networking or speed dating or something.