Nattō is associated with both health/wellness food culture, which as we all know has fascistic roots and is associated with ideas of purity and national strength.
Further reenforcing this is that Nattō is considered a food only Japanese people like, a pillar (albiet a minor one) of ethnonational identity. Consider: 30% of people who eat it do not enjoy it but instead eat it based on aformentioned health reasons[1]. Offering nattō to people in order to see their repulsed reactions is an act of humiliation, reenforcing the superiority of the Japanese character and identifying an out-group.
Anyway it’s ok, a little mild. More stale coffee than cheese, I keep craving it though and am now fermenting my own


I can’t do it half as well as Mary can.
I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy: