Goukon is a (marginally) popular new(ish) kind of arranged dating service where groups of strangers can get to know each other. Usually these are “business casual” affairs in bars and restaurants.
This particular article discusses what kinds of men should not even bother showing up. My favorite is the quote from a woman discussing her frustrations with men who wear sweat pants and jerseys to the goukon. She says “He should be a little more considerate of those of us who took time to dress stylishly”.
Goukon is another excellent example of the group emphasis that is so prevalent in Japanese culture. In the West similar events would maybe be things like speed dating where everybody has one-on-one time.