I'm the author of that post, the 'insufferable self-absorbed hipster.'
It was a typo - I'd meant 'kamei-suru' but was pretty bad at Japanese when I first arrived (and still am not very good, but continue to learn and practice even after having left the country). It's this:
+
And basically refers to 'becoming a part of the group' by engaging and participating in the group's activities. I think in hindsight it may have a much more limited function.